sábado, 12 de março de 2016

The Belmont Mine and an Emerald’s Journey from Mine to Market

The Belmont Mine and an Emerald’s Journey from Mine to Market

 Andrew Lucas, Duncan Pay, Shane McClure, Marcelo Ribeiro, Tao Hsu, Pedro Padua

 
A Mine-to-market Ring
The emerald in this ring traveled through the entire mine-to-market value chain, from the earth of Brazil’s Belmont mine to a custom jewelry manufacturer and retailer in Thailand. Photo courtesy M. Suradej Joaillerie

INTRODUCTION: BRAZIL

Brazil gained its independence in 1822 from Portugal, which had ruled the country since the early 1500s. Today, Brazil is South America’s largest and most populous country, and also its strongest in economic terms. With a total area of 8,514,877 square kilometers, Brazil is the fifth largest country in the world, with abundant natural resources. A leading contributor to its economic strength is the mining of precious metals, iron ore, manganese, nickel, phosphates, tin, rare earth elements, uranium, and petroleum.

Another of Brazil’s main economic resources is its agricultural output, which includes crops such as coffee, soybeans, wheat, rice, corn, sugarcane, cocoa, citrus, and beef. Its largest industries include textiles, shoes, chemicals, cement, lumber, tin, steel, aircraft, motor vehicles, and machinery. Brazil is sixth in the world in the size of its labor force, which employs over 107,300,000 citizens. Its $244.8 billion in annual exports places it 23rd in the world. China is its main trading partner, followed by the U.S.

Rainbow at Iguazu Falls查看图库
Amazing Brazil
The people of Brazil are as diverse as their natural resources. The European population includes those of Portuguese, German, and Italian descent. There is also a large African population held over from the days of the slave trade, as well as indigenous people and many people of mixed ethnicity. This diversity has given rise to the country’s extremely rich culture.

Brazil is also rich in terms of its gemstone and jewelry industry. For decades, Brazil has been a leading supplier of colored gemstones, including emerald, amethyst, citrine, agate, tourmaline, topaz, alexandrite, cat’s-eye chrysoberyl, opal, iolite, garnet, and many others.

MINAS GERAIS

When you translate the Portuguese name Minas Gerais into English, it literally means “general mines.” Mining is one of the most important industries in this large Brazilian state. The northwest part of the state is known for its huge pegmatite deposits that produce tourmaline and other colored gemstones. The business center for the mines is Governador Valadares. This city hosts gemstone cutting, trading, and industry shows. Diamonds have also been produced in the area around the town of Diamantina.

The southern part of the state has massive iron-ore mines and a railway to transport the ore to the coast. Near the UNESCO World Heritage Site of Ouro Preto are the world’s only commercial sources of imperial topaz and a famous source of pink topaz. The name Ouro Preto translates into “black gold,” alluding to the historic importance of gold mining to the area.

Gemstone Heaven
Pink topaz is just one of the many gemstones mined in the state of Minas Gerais. Photo by Eric Welch/GIA.
The capital of Minas Gerais is Belo Horizonte, a city of over four million people. It is a center for Brazil’s gem and jewelry industry. A number of important gemstone cutters, jewelry designers, and jewelry manufacturers are located there.

Belo Horizonte查看图库
Gems and Jewelry in Belo Horizonte

ITABIRA

Itabira lies in the southeastern part of Minas Gerais and has over 100,000 inhabitants. The town’s most important industry is iron-ore mining and its most important company by far is Vale, the iron-ore mining giant. Vale is the third largest mining company in the world, the largest producer of iron ore, and the second largest producer of nickel. The largest iron-ore mines near Itabira are Cauê and Conceição. The ore is transported to the Port of Tubarão in Vitória, in the state of Espírito Santo, by the Vitória Minas railroad that goes across the entire state of Minas Gerais. While iron-ore mining supports the town’s economy, emerald mining is important to the global colored gemstone industry.

General Location Map South America
Brazil Country Map 
While Itabira is better known for its iron-ore mining, the Belmont mine has made it
famous in the gem industry for emeralds.
As the most productive emerald region in the country, Itabira is also the only place where large emerald mining companies are located. Among them, Belmont is the largest. It’s also one of the world’s most sophisticated and important emerald mines. Established in 1978, this family business is now entering its third generation.

Belmont Mine
While small compared to the area’s iron-ore mines, the Belmont emerald mine is the largest colored gemstone mining operation in Minas Gerais. Photo by Andrew Lucas/GIA.

BELMONT MINE HISTORY

Our team interviewed Belmont mine manager and family member Marcelo Ribeiro at the original pit mine, where emeralds were first discovered. He related the entire amazing story of how this area came to be one of the most sophisticated colored gemstone mining operations in the world.

Belmont Mine Location
Belmont Mine Location
The Belmont mine has been operating since 1978. It’s located 13 km (8 miles) southeast of the town of Itabira. Map provided by Belmont mine.
The source was discovered in 1978 by Mauro Ribeiro, the owner of the farm where the property lies. Mr. Ribeiro was born on the farm and lived there until he moved to Itabira to participate in the construction business. After starting an iron-ore mining company in Itabira with several hundred employees, he began to suffer from the stress of overwork and his doctor told him he needed a vacation.

Being more of a country man than a traveler, he returned to the family farm to relax for a month. Mr. Ribeiro had inherited the farm from his parents. Then, after buying out all the shares from his other family members, he kept the farm as a hobby and raised cattle on it.

Mining and Farming
The Ribeiro ranch operation continued through the early 1980s, when the mine was in its early stages. Courtesy Belmont mine.
When Mr. Ribeiro arrived at the farm he used a front loader to make a small dam near a stream in the south of the property to create a watering spot for the cattle. As he was excavating the site, and the small lake started to fill with water, some green stones washed up the sides. Unbeknownst to Mr. Ribeiro, he had reached an area where emeralds formed.

Mauro Ribeiro
Mr. Mauro Ribeiro discovered emeralds while making a small dam, although he wasn’t aware of their value at first. His use of bulldozers continued through the early years of mine production. Courtesy Belmont mine.
Mr. Ribeiro was very happy with the small lake he built himself and went back to running his company, feeling more relaxed. He did not know what the green stones he saw were and didn’t pay that much attention to them.

A rail line near the Belmont property links Itabira to the harbor and is used to transport the coal from the massive coal mine nearby. A railroad track crossing point, operated manually by a lever, was located near Mr. Ribeiro’s new manmade lake. The lever operator at the track crossing was from Teofilo Otoni, a city in Minas Gerais that had become a gemstone cutting and trading center for many of the emeralds from the state of Bahia. Having observed emerald cutting and trading in Teofilo Otoni, the railroad worker had some knowledge about emeralds and emerald rough.

Entrepreneur
Mauro Ribeiro (right) had long been an entrepreneur. Even before working in the iron-ore industry, he bought empty oil barrels in Itabira and sold them in Belo Horizonte for a profit. This enterprising and independent spirit led him to venture into the gemstone industry once the opportunity presented itself. Courtesy Belmont mine.
One day the railroad worker decided to jump the fence and get some water out of the newly made lake. As he explored the lake area, he saw the green stones, which he recognized as emerald. He found Mr. Ribeiro and made a proposal: He would collect as many stones as he could, take them to Teofilo Otoni, sell them, and split the money fifty-fifty with Mr. Ribeiro. The deal was agreeable to Mr. Ribeiro as he had no idea about emeralds at that time. When the railroad worker brought Mr. Ribeiro’s share to him, he was amazed. After just a week of picking up stones by hand, the worker was able to bring Mr. Ribeiro more money for his share than he made in the iron-ore business in a month.

Belmont Mine, 1983
A lot of hard work, clever thinking, and political maneuvering was required between 1978 and 1983 to bring the mining operation to the state. Courtesy Belmont mine.
Mr. Ribeiro called Pedro, a friend and mining engineer in the iron-ore industry who lived in Belo Horizonte. When Mr. Ribeiro told him that he had emeralds on his property, Pedro told him it was impossible, as there were no emeralds in the area around Itabira. He instructed Mr. Ribeiro to heat the stones in a flame for a while and see if the color changed, thinking they might be aquamarines. Mr. Ribeiro did so and called Pedro to report that there was no color change. When Pedro came to take a look, he confirmed the stones were emeralds.

Mr. Ribeiro was very experienced in iron-ore mining and knew about the laws regarding minerals and mining rights in Brazil. As in other parts of the world, ownership of the land does not mean you own the mineral rights. There are various criteria involved in qualifying for the mineral rights on property you own. Mr. Ribeiro went to the Brazilian government’s mining department to apply for the mining concession on his property.

A concession is usually granted to the first person or company to properly apply for it. Shortly after Mr. Ribeiro submitted his application, many others applied for the mining concession on his property, as the news was spreading fast. In the years 1978 through 1979, over 500 independent miners, called garimpeiros, invaded the emerald-bearing area on the property, built tents, and started mining.

While the mining concession application was slowly working its way through the Brazilian bureaucracy, Mr. Ribeiro made a deal with the garimpeiros. He organized them and laid down rules: There would be no guns, no alcohol, and no women on the property. He also made an arrangement where everything that was mined would be grouped together as parcels and sold. The revenues would be split among everyone. He also constructed a fence around the mining area and informed the miners that outside the fence were his farm, his cattle, and his family, and they must be respected.

Garimpeiros Camp
In 1979, the garimpeiros had their own camp on the Belmont property. Courtesy Belmont mine.
At the time, there was a lot of corruption in the Brazilian government and Mr. Ribeiro thought that his mining concession application was taking too long to get approved. If it was rejected on some technicality, he feared that the next application would be accepted, possibly as the result of a bribe. Mr. Ribeiro went to a politician he had known for years and had supported in elections, and expressed his concerns about the application and the number of garimpeiros invading the property.

The politician demanded payment to help with the mining concession application, which offended Mr. Ribeiro. He resented being asked for a bribe to do what the government should be doing anyway, especially by someone he considered a friend and someone he had supported in the past without asking for favors in return. The politician said this was how things worked and Mr. Ribeiro replied he would think about it.

Mr. Ribeiro told his wife he was going to Brasilia, the capital, and promised to return when the mine was his. Standing in front of the Mining Bureau building, he began wondering how he could get the application approved or even find out where it was sitting. As he watched people coming and going, he saw an honest looking man going in and asked him if he worked there and what he did. The man replied that he was one of the people who cleaned all the offices. Mr. Ribeiro explained the situation to the man and asked if he could help him find out where his application was and who he should speak with.

The janitor agreed to help, and later informed Mr. Ribeiro that his paperwork was on the desk of the Minister of Mines with a lot of other paperwork, and it was all very disorganized and neglected. Mr. Ribeiro asked the janitor if there was any way he could bring it to the attention of the Minister. After all, his application had been sitting there for a very long time.

The janitor took it upon himself to speak with the Minister, and said, “Mr. Minister, I noticed that these papers that need signing had been misplaced, and I organized them for you with the one waiting the longest on the top.” The Minister was grateful to the janitor for cleaning up the disorganized piles of papers and signed Mr. Ribeiro’s application by the next day. Mr. Ribeiro was so happy that he gave the janitor enough money for a new car. He returned home with the signed mining concession and it was officially published in the papers.

Aerial View
This aerial view shows the mine and the area around it as it appeared in the early 1980s. Courtesy Belmont mine.
Mr. Ribeiro stopped working in the iron-ore industry and formed a company to mine the area in an organized way. He brought the entire family into the business as there was a lot of work involved in getting a professional mining operation underway as well as security problems such as theft and invasion to deal with.

Garimpeiro Damage
The Belmont property suffered significant damage from the numerous pits dug by the garimpeiros. Mr. Ribeiro eventually ended their involvement in the operation. Courtesy Belmont mine.
In late 1979 to 1980, heavy rains flooded the mining area. With operations halted, they brought in pumps to remove the water and looked at ways to improve their mining technology and methods. At the same time, the garimpeiros became interested in emerald mining at Santa Terezinha in the state of Goias, and many of them moved to that area. This alleviated some of Belmont’s theft and invasion problems for a while, but limited the mine’s manpower.

These circumstances allowed time for establishing a proper mining plan for the deposit. Mining engineers were brought in, the open pit was developed, the processing plant was built in 1980 using a conveyor belt hand-picking system, and production resumed at even stronger levels.

Security
Even in the early 1980s, security was a major concern. Belmont introduced a closed-circuit system to monitor and record activity around the mine. Courtesy Belmont mine.
First Sorting Plant
Belmont built its first sorting plant in 1981. Courtesy Belmont mine.
Hand Sorting
At the first sorting plant, all sorting was done by hand from conveyor belts. The sorters placed emerald-bearing schist into suspended buckets. Courtesy Belmont mine.
Another obstacle arose when the garimpeiros who had previously worked the property hired a lawyer to help them return to the area. The emerald yield at Santa Terezinha proved to be not as high as they hoped. Their lawyer went to the government to claim that Mr. Ribeiro was not paying the required tax. The government then audited his bank account.

Mr. Ribeiro’s problem was that when he was selling emeralds for the others, all the proceeds were coming through his account. He gave the miners their share in cash, but he was paying the tax only on his 20 percent share. This made it appear as if he was not paying enough tax. There was no way to successfully fight the government over the tax bill so he had to sell a lifetime’s worth of possessions to raise enough money to pay the tax and keep possession of the mine. Luckily, a mining concession is not considered an asset so he was able to protect it during those tough times.

Dragline Mining
In 1980, a dragline system was used in the pit mine. The ore was scooped up into a scraper and loaded onto a truck for transport to the processing plant. Courtesy Belmont mine.
By 1982, the family’s legal problems were behind them. They still owned the mining concession, so they resumed mining and implemented larger-scale mechanized methods. At the time, they utilized a dragline pit-mining method. They dragged the earth up in buckets, taking mud, overburden, and ore to be sent all together to the processing plant. The mass of materials made processing difficult.

By 1985, they had purchased their first hydraulic shovel, an expensive piece of equipment that was rarely used for colored stone mining in Brazil at the time. Despite warnings by the salesperson, who suggested something smaller for emerald mining, the equipment paid for itself within a month. After that, mining was less expensive, as the stones were brought closer to the surface, making them easier to extract.

Hydraulic Shovel
In the mid-1980s, the Belmont mine incorporated a hydraulic shovel into their operation. It was a big investment rarely used in colored stone mining at the time. Courtesy Belmont mine.
The operation remained strictly open-pit until the mid-1990s, but it became more difficult as the pit grew deeper and larger, with more and more waste removal required. At that time, exploration and core sampling became more critical, along with more sophisticated mining methods. One of Belmont’s geologists suggested making vertical shafts to get a better understanding of the geology, as well as to determine future production rates and the potential for underground mining. They thought underground mining could be useful and economically viable in areas where the quantity of overburden that needed to be removed to reach the emeralds was prohibitive. Studying the mine with an underground perspective would also help to plan future mining areas. Their first shaft was 35 meters deep, in the area of the original pit and, as expected, it provided helpful information for mine planning.

Belmont 9.29 ct Emerald
This 9.29 ct emerald was recently recovered from the underground mine at Belmont. Early underground exploration proved to be highly worthwhile, as underground mining has become an increasingly important contributor to Belmont’s overall production. Photo by Robert Weldon/GIA courtesy Belmont mine.
Core sampling began in the late 1970s and intensified in the 1990s. At first, they hired a contractor for core drilling rather than using their own geologist. But the contractor tried to use Belmont’s own data to make surveys for nearby properties, so by the late 1990s, Belmont put together their own core-drilling team. In 2001, just when planning for future mining activities at Belmont was heavily underway, Mr. Ribeiro’s grandson, Marcelo Ribeiro, graduated college with a degree in mining engineering.

Early Core Drilling
Mauro Ribeiro and an initial geological team began core drilling in the late 1970s to better understand the deposit’s potential. Courtesy Belmont mine.
The major decision that needed to be made at that time was whether mining the open pit was possible for a longer period of time and whether it would be economically viable. Marcelo was involved in that decision-making process and the family decided to invest more heavily in the open-pit operation. They installed more pumps for water removal, which lowered the water level to allow deeper mining.

Marcelo’s Diploma
Marcelo Ribeiro graduated with a degree in mining engineering in 2001. He was instrumental in many of the technological developments at Belmont. Courtesy Belmont mine.
These events led to the development of what is now one of the highest-technology colored gemstone mines in the world. A constant quest for knowledge about the deposit, aided by new technology, has led the way to continued development. Belmont management is tirelessly devoted to fully mapping out the deposit, learning where the emeralds are, and determining the best mining methodology and most effective technology. This devotion is what brought the mine to its present state.

Ribeiro Family
The entire family came together for Mauro Ribeiro’s 70th birthday party. The group included a young Marcelo, seen in the top row, third from the left. Courtesy Belmont mine.
BELMONT MINE HISTORY
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BELMONT GEOLOGY

Previous regional field mapping shows four main geologic units underlying Itabira, Santa Maria de Itabira, and Nova Era: (1) an Archean cratonic basement composed of gneisses and granitic rocks; (2) an Archean greenstone belt (mafic oceanic crust accreted to the continental margin during subduction); (3) Lower Proterozoic metasediments that belong to the Minas Supergroup; and (4) Medium Proterozoic metasediments that are essentially quartzite. Two main tectonic events influenced this area: the Paleoproterozoic (~2.1 Ga—billion years ago) transamazonic orogeny and the Neoproterozoic Brasilian orogeny (~600 Ma—million years ago). The latter belongs to the global Pan-African frame.

In Itabira, the Early Proterozoic Minas Supergroup includes, from bottom to top, paragneisses that formed through the metamorphism of sedimentary rocks; greenschists; the Caraca group, made of micaceous quartzites and some phyllites; the Itabira group, containing the most economically important itabirite and hematite-iron ore; and the Piracicaba group, composed primarily of quarzites, sericites, and phyllites. The entire sequence was subjected to regional metamorphism.

Regional Geology
Regional Geology
This illustration outlines the regional geology around the Belmont mine. Adjusted from
Hanni et al., 1987
The formation of emerald at Belmont is a result of the metasomatic reaction between beryllium-rich pegmatites and chromium-rich ultramafic rocks. At Belmont, the deeply weathered Archean greenstone belt is in contact with Borrachudu metagranitoids and fluorite-bearing foliated metagranitoids. The mafic formations were metamorphosed to biotite, talc-chlorite schists. The schists dominate the mining area at Belmont and are 750 to 1000 meters wide, striking NE to SW.

A number of pegmatites intruded into the schists. Intense weathering resulted in a lot of the pegmatites converting to kaolin, and quartz pockets are distributed between the metagranitoids and the schists. Emeralds are found only in the metasomatic reaction zones within the chlorite schist and black phlogopite schist or in the highly altered pegmatite bodies.

The origin of the pegmatites is still being debated. Some researchers propose that they are related to the Brasilian orogeny (about 500 Ma) and others think that they formed during the earlier Transamazonic orogeny (about 1.9-2.1 Ga), with some of the lower-temperature minerals such as biotite rejuvenated by the later Brasilian tectono-thermal event.

Cross-section of Mining Area
Cross-section of Mining Area
This east-west cross-section clearly shows the mining area’s different geological units and their thicknesses. Drilling cores crossed through all the units. Courtesy Belmont mine.

BUSINESS MODEL

It’s difficult to predict the actual life of a mine because the mining rate depends on many economic factors. When demand is high, mining activity is high, and when demand decreases, such as during a recession, mining activity is reduced. Marcelo has no fear of running out of emeralds, but he is concerned about economic factors that can make mining expensive, such as recessions that lower emerald’s per-carat price, fluctuations in currency rates, and even fuel costs.

The Belmont Mine
This overview of the Belmont mine shows the original pit with the processing plant in the background. Because Belmont is a large-scale colored gemstone operation, global economics have a strong influence on its mining costs. Photo by Andrew Lucas/GIA.
This has led Belmont to pursue operations that take it higher in the value chain. While they have continually improved their sorting, parcel creation, and customer base, several years ago they moved into manufacturing and selling cut stones rather than just rough, hoping to not only increase the return on the emeralds they mine but also to make it more economically viable to continue mining, and to prolong the life of the mine.

Belmont Cutting Facility
Belmont now cuts the majority of their own rough production, moving their business
farther up the value chain. Photo by Andrew Lucas/GIA.
Belmont now cuts the majority of the facet-grade rough they produce—about 70 percent by value, about 60 percent by volume. When deciding what rough they will retain for cutting and what rough they will sell, Belmont looks primarily at market demand and cost effectiveness factors. Currently, they cut all their facet-grade rough in Brazil. However, labor costs are not as low as in other areas of the world, so they must determine if a faceted stone fashioned in Brazil can be priced at a globally competitive level. Most of their carving, bead, and cabochon-grade material goes to Jaipur, India.

A SPECIAL STONE’S PROGRESS

While GIA field gemologists often visit mines and study the complete mine-to-market value chain, it is not often that we can follow a particular stone from the mine to the final consumer. We had that chance with a 29.8-gram piece of rough from the Belmont mine. This rough came out of the underground mine at a level 654 meters above sea level and 100 meters underground. As is usually the case with both underground and pit mines, the stone was not discovered during the mining process itself. It was still in the schist after the blasting and extraction processes were complete.

Going Underground
Our mine-to-market emerald came from the underground operation, which required significant investment and heavy equipment like this front-loader. Photo by Duncan Pay/GIA.
Belmont’s sophisticated optical sorter was the first to “see” the stone. The first human saw it right after optical sorting, in the “safe room” where the emerald-containing ore is stored. No one noted its quality, however, until it came to the sorting and grading facility in Itabira and wound up on mine manager Marcelo’s desk. It was actually Marcelo’s mother who noticed it. She called Marcelo over to see something “extra special.”

Inside the Sorter
The Belmont mine relies on the sophistication of its optical sorters to detect valuable emerald rough. Photo by Andrew Lucas/GIA.
The Ribeiro family always checks every production first. When we asked Marcelo how often he finds such large and high-quality crystals, he replied, “It’s a matter of luck. But I believe what brings me luck is hard work. God helps those who work with passion. Belmont mine is amazing: Every production may bring a surprise. I would say we can have one to three stones with that size and quality per year.”

Original Rough
The original rough of our mine-to-market emerald was impressive and showed great potential. Photo by Andrew Lucas/GIA.
Marcelo showed the stone to his cutter and they discussed their cutting strategy. Marcelo did not allow him to start cutting, as he wanted to let the GIA team set up and document the cutting process. He told his chief cutter, Donizete, that “tomorrow, my GIA friends will make a video,” so he could show them what he has learned in 38 years of cutting emeralds.

As Donizete turned the stone to examine it from all angles, his eyes sparkled and he said, “Listen, you know this is my life, I love what I do and I am very happy your friends are coming to see us. I will do my best and God willing we will have one beautiful stone out of the stones cut from this rough that weighs over 15 carats.”  Marcelo jokingly asked, “Do you want to sleep with the stone tonight?” Donizete replied, laughing, “I would, but my wife is very jealous.”

Planning the Sawing
Marcelo and his chief cutter spent a great deal of time discussing the sawing, preforming, and cutting of the large emerald rough. Photo by Andrew Lucas/GIA.
Before they put the stone into the safe for the night, Marcelo and his cutter had a bit more discussion about their strategy for finishing the stone and about where to make the first saw-cut. Marcelo tried to push Donizete for more details about his plans for cutting the emerald but Donizete just replied, “Don’t worry, the stone will tell us what to do.”

OPEN-PIT MINING

For four to five years after the mining concession was established, they continued open-pit mining at the original location—pit #1. But as the pit became deeper, water problems started hampering the operation. The pit was at a low area of the property, very near water level, and rains made flooding a constant problem. To compensate, they moved some mining operations northward.

OPEN PIT MINING
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They also decided to continue mining pit #1 and invested in more pumps to remove the water, adding years to the pit’s life. At the time of our visit, pit #1, called the old pit by Belmont personnel, was still being mined, although it was becoming too expensive and approaching the end of its productive life. Marcelo estimates they will be mining the old pit for another two years.

Pit #1
At the time of our visit, there was some rainwater at the bottom of pit #1. The water
reflected the hydraulic shovel as it loaded the truck. Photo by Andrew Lucas/GIA.
Hydraulic Shovel
The hydraulic shovel loads earth into a truck for transport out of pit #1, which is now so deep that it has reached the hard-rock phlogopyte schist. Photo by Andrew Lucas/GIA.
Currently, the original pit has one mechanized shovel going deeper and another continuing the pushback on the high wall. In the past five years, Belmont has gone about 35 meters deep into the original pit, which is approximately 150 meters by 100 meters in size. Activity was constant while we were there, with the hydraulic shovel removing waste and exposing the reaction-zone ore. They removed the highly weathered white granite overburden to reveal the dark phlogopite reaction-zone ore beneath it. In the earlier mining stages, the weathered phlogopite had been golden in color and easy to remove. At the current depth, the phlogopite reaction zone was dark, hard rock similar to what is encountered in an underground mine.

We observed another type of schist, rich in silica. Marcelo said they call it fool’s schist, after fool’s gold, because it does not contain emeralds. Also, when mining began, the original pit had a concentration of emeralds that had washed down from the hillside into the pit area, making this eluvial emerald deposit easy and profitable to mine. Alluvial river gravel beds of emerald are extremely rare, but these had been weathered free and not traveled far so they were still intact.

Fool’s Schist
Not all the schist in the pits contains emerald. Some that contains no emeralds is referred to by the miners as fool’s schist. Photo by Andrew Lucas/GIA.
While Belmont cannot be as accurate with value estimations as iron-ore mines or gold mines, they feel, on average, they can come up with fairly good predictions. Marcelo estimates there are at least 10 to 15 more years of open-pit mining at Belmont. Pit #1 will also prove very useful over the coming years because it can accommodate all the tailings from the processing plant and all the waste rock from other mining operations. By not having to transport tailings and waste material very far, mine operators can save considerable costs. This cost-saving will be one factor that helps extend the life of the mine.

Current and Future Mining Activities
Current and Future Mining Activities
Future mining pits have already been planned based on very detailed exploration work by Belmont geologists. Current mining operations include both open-pit and underground mining. Courtesy Belmont mine.
There are two other open pits being developed at Belmont, with progress moving from south to north. They are identified as pit #2 and pit #3. The third pit is 500 meters from the original pit, with pit #2 between them. Pit #2 is about 200 meters by 80 meters in size, and expected to reach 300 meters by 100 meters. Pit #3 is expected to be 100 meters by 100 meters.

CORE DRILLING AND ANALYSIS

Open-pit mining at Belmont still has a long potential life span as it continues into the northern areas of the concession. The investment in core drilling over the last 15 years is paying off in helping to plan for open-pit operations over many more years.

CORE DRILLING
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Belmont has core-drilled over 15,000 meters, at an average cost of about $200 USD per meter. The Belmont geologists have become experts at reading the lithology of the phlogopite schist core drillings. They send the cores for chemical analysis, then feed the information into a mathematical model Belmont is developing to predict emerald concentrations as well as the quality of emerald in the ore. Core sampling follows the standard mining-block model, where they divide the ore into cubic blocks by three-dimensional computer modeling. Each block is then assigned an estimate of the revenue that can be recovered by mining that block.

Core Drilling
For the GIA team, Marcelo Ribeiro explains the importance of core drilling in planning future mining efforts. Photo by Duncan pay/GIA.
The data is compiled from core samplings and mining activity. Projected revenue is determined by mathematically estimating the quantity of emerald in the block, and to some degree its quality and value. This combination of information makes analysis more difficult than it would be for other commercial minerals.

Their quality estimate is actually an estimate of the color quality of the emeralds in the block. Through their mathematical chemistry model, they can measure the amount of chromium present, which helps them understand the potential quality of the green color. By measuring the iron and vanadium content, they can analyze the potential strength of the color modification by blue or yellow hues.

THE IMPORTANCE OF CORE SAMPLING
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They cannot yet accurately estimate the crystallization or clarity. However, they are working on understanding the relationship between the beryllium, chromium, iron, and possible other elements to potential crystallization. This will not tell them if mechanical cracks are present but they hope to be able to predict if the crystals will be milky or clear.

Core Samples
Core-drilling samples provide the information needed for planning mining locations as well as for analyzing potential emerald quality. They also act as a permanent reference. Photo by Andrew Lucas/GIA.
3D Modeling from Core Sampling
3D Modeling from Core Sampling
Belmont has created a 3D model based on core-drilling data from many areas of the mine. The model is very important for planning future mine development. Courtesy Belmont mine.

UNDERGROUND MINING

In 1994, the current ramp-style underground mine started out as three small vertical shafts from which horizontal tunnels called galleries were excavated with the goal of better understanding the formation of the emerald in the hard rock phlogopite schist. At that time, Belmont had only been mining the weathered phlogopite schist in the pit mine. Observing the emeralds underground in the schist provided a better idea of the ratio of emeralds to rock, along with the direction of emerald formation and reaction zones. The vertical shafts were for research, and to study the possibility of progressing to underground mining.

UNDERGROUND MINING
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Vertical Shaft
When GIA visited the Belmont mine in 2004, the only access to the underground tunnels
was by a vertical shaft. Photo by Andrew Lucas/GIA.
Overall Mining Area
Overall Mining Area
This is a 3D view of the whole mining area. Open pits are located primarily within the altered ore body, while the underground operation focuses on the compact ore body. Courtesy Belmont mine.
After several years, Belmont felt confident enough to make the considerable investment required to develop a ramp-style underground mine. The ramp needed to be large enough to allow front-loaders and trucks to enter the mine, work in the mine, and haul ore out of the mine. The original vertical shaft was integrated into a ventilation shaft for the ramp mine. Exhaust pipes are used to help remove the dust through the vertical shaft. The shaft also serves as an emergency exit. One of the keys to underground mining is ventilation. Besides the vertical shaft, there is a piping system that provides air throughout the mine.

Ventilation Tubes
Wires on the left side of the tunnel provide electricity while tubing on the upper right provides ventilation. Photo by Andrew Lucas/GIA.
During full production, 30 to 40 truckloads of material can be removed from the underground mine, totaling about 400 to 500 tons of ore a day. During our visit they were removing about 15 truckloads a day, for a total of about 200 tons of ore. The current state of the underground mine is very impressive, with between two and three kilometers of underground tunnels. The main ramp is about 500 meters long, from the surface to the deepest point in the mine. This ramp is the main road into the mine and it is 4X5 meters in size. This allows enough space for front-loaders to load trucks, and for the trucks to move freely in and out of the mine.

Loading the Ore
This front-loader is poised to load ore into a truck. It sits on a raised platform to make loading easier. Photo by Andrew Lucas/GIA.
With gemstone mining, it can be advantageous to mine at multiple locations. Belmont’s current production comes half from the underground mine and half from the open pit. It is difficult to predict the quality of material obtained at any production point at any location. By mining both the underground mine and the pit mine, Belmont gets a good range of material for parcels. However, in 20 years the underground mine may need to produce a far higher percentage of ore. Because of this, Belmont has designed the underground mine with the goal of doubling the current rate of production.

While it is easier to mine the open pit, the underground mine requires less removal of waste, as mining is taking place directly in the phlogopite schist. To mine the current underground mine as an open pit, Belmont miners would have to first remove 70 meters of overburden to reach the schist. They determined it was economically more prudent to mine this area as an underground mine.

MINE PLANNING
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The underground mining process begins with blasting to remove the phlogopite schist. Scrapers pull the schist that has been blasted free down to the main ramp. There, it can be loaded into the trucks and hauled to the processing plant. The blasting opens up what Belmont calls mining panels in the rock. The panel we saw was a reaction zone about 1.5 meters thick. Belmont had been following this reaction zone, blasting it free and pulling it down with the scrapers. A scraper consists of a winch that hauls buckets of material down from the mining panel through the tunnel, to a point where it can be picked up by a front-loader and then taken to the truck. The truck then takes it out of the mine through the main ramp.

Mine Ramp
Being able to drive trucks down the ramp to the mining area gives underground mining a huge advantage for moving material, but it also requires a large initial investment to make the tunnel wide and deep enough to accommodate large trucks. Photo by Duncan Pay/GIA.
3D Map of Underground Mine
3D Map of Underground Mine
The underground mining operation is well developed, with ramp-style entrances large enough to accommodate trucks, and numerous galleries and mining panels that are constantly being mapped out as mining progress continues. Courtesy Belmont mine.
The stones in weathered phlogopite mined from the open pit tend to be smaller than those in the hard-rock phlogopite of the underground mine. However, extraction of the weathered phlogopite in the open pit does not require blasting so there is less damage to emerald crystals. In the end, the stones from both source types often wind up about the same size and quality. Also, the original pit is now so deep that it has reached the level of hard-rock phlogopite schist.

Ore Truckloads
Truckloads of ore leave the mine for the processing facility, which has been revamped to handle hard-rock schist. Photo by Andrew Lucas/GIA.
Intrusion
In the emerald-bearing zones, white beryllium-rich pegmatite intrudes into chromium-rich phlogopite schist. Photo by Duncan Pay/GIA.

STATE-OF-THE-ART PROCESSING

At the moment, most of the ore from the pit-mining operation looks the same as that from the underground operation. This is due to the fact that most of the pit-mining production is from pit #1, which means it comes mostly from phlogopite schist that is similar to the hard rock in the underground mine. The golden, weathered phlogopite schist has mostly been mined out of pit #1 and they are into the hard-rock schist at this point. For this reason, the processing plant is geared primarily to processing hard-rock schist, where before it was geared mostly to processing weathered schist. Pit #2 has also reached hard-rock phlogopite schist so it requires hard-rock processing methods.

PROCESSING THE ORE
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The process starts when the trucks bring the schist to the processing plant and unload it into the first grating. Any schist smaller than 500 millimeters falls through the grating and into the first jaw crusher. A hydraulic hammer breaks up the large pieces of schist so they can fit through the first grating. A series of crushers and screens reduces all the schist down to 40 millimeters in size. Schist that’s less than 40 millimeters in size goes to the hydro-clean, which subjects the schist to high water pressures to thoroughly clean it and make the emeralds more visible to the optical sorter.

Processing Facility
Belmont invested heavily in converting their processing facility to handle hard rock instead of the loose dirt they had focused on in the past. Photo by Andrew Lucas/GIA.
Previously, water cannons were used to crush and wash the weathered phlogopite schist. These were ineffective against the hard-rock phlogopite Belmont is currently mining, so crushers and the hydro-clean system have taken their place. Hydro-clean technology is from Germany and is much better than water cannons because it uses much less water and energy, and has much higher capacity.

Directly after hydro-clean processing, screens separate the schist by size. There are three size classifications: small, at less than 10 millimeters; medium, between 10 and 20 millimeters; and large, from 20 to 40 millimeters. Belmont uses two optical sorters—one for the under-10 millimeter schist and the other for the medium and large material.

Dumping the Ore查看图库
The Processing Plant
The original processing plant, built in 1981 and operated until October 2013, was designed for the weathered phlogopite schist ore. Significant investment was needed to convert the plant for processing the hard-rock phlogopite schist. They expect the new processing plant to operate for about as long as the original. Although the investment was substantial, it allows them to efficiently process the type of ore they are now mining and to make way for the potential production capacity of the future. The current plant can process three times more than the prior plant, with half the labor. By increasing production capacity and lowering operating costs, the processing plant is one of the measures Belmont has enacted to increase the mine’s productive life.

PRODUCTION

Currently, Belmont needs to move an average of 8 to 10 times more waste rock than reaction-zone ore from its open pits. This means that to recover one ton of phlogopite schist reaction zone, Belmont has to move 8 to 10 tons of waste. Out of the one ton of reaction-zone ore, Belmont recovers an average two grams of emerald rough, which yields on average about two carats of cut stones. Overall, Belmont mines 11 tons of rock for every two carats of cut emeralds from its open pits.

PREDICTING EMERALD QUALITY
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Underground mining requires less rock handling and waste. In the underground mine, Belmont mines one ton of waste to one ton of reaction-zone ore, so they average two tons of rock mined to two carats of cut emerald. Fifty percent of Belmont’s production comes from open-pit mining and 50 percent from underground mining. At this moment, most of the open-pit production is from pit #1. That will change after a couple of years and pits #2 and #3 will dominate open-pit production.

Locked Boxes
At the mine’s on-site processing plant, Marcelo Ribeiro looks through the contents of the locked boxes to analyze the mine’s rough production. The boxes will be sent to the sorting house in Itabira. Photo by Andrew Lucas/GIA.

PROTECTING THE ENVIRONMENT

Belmont places a high priority on environmental protection and restoration. The reasons for this include:
  • They feel it is the right thing to do.
  • The mine is their home, where their ranch still exists and the family has a connection to the land.
  • The environmental regulations in Brazil have become very strict, especially as the mining operation becomes larger.
  • They feel there is a growing marketing advantage to offering ethically mined gemstones as well as promoting environmentally sound, “green,” practices for a green stone like emerald

RECLAMATION AND REFORESTATION
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One of the main concerns in any mining operation is water contamination. Water is necessary for gemstone mining, especially during the processing of the ore and recovery of the gemstones. The main environmental problem with gemstone mining is that the water becomes contaminated with particles from the overburden dirt and gravel, and in this case, also schist, as it washes away these materials to reveal the gemstones.

Reclamation Ponds
Belmont’s water reclamation system consists of a series of gravity-fed ponds. Photo by Andrew Lucas.
Belmont uses a seven-pond filtration system to remove particles and to further purify the water used during mining and ore processing. The ponds are at slightly different elevations so gravity causes the water to pass from one pond to the other, becoming purer as it progresses. The pulp (water plus solids smaller than 0.06 mm) passes slowly through the ponds as the water filters through the system, and the solid particles settle into the ponds. Belmont routinely cleans the ponds, removing the particle sediments and bringing them back to the mining area to be used as backfill.

By the time the water is returned to the river, the pond filtration process has removed 99.5 percent of all particles and also introduced oxygen to the water. At the end of the process the water exceeds all parameters to qualify for human consumption and is cleaner than the water in the river it is being returned to. The process cleans 200 cubic meters of water an hour. Belmont is working to refine the process for 100 percent removal of particles from the water.

Besides water reclamation, another goal of green mining is to refill pits and other mined areas and reforest those areas. The mining process removes materials that do not contain emeralds to reach the mineralized zones. Belmont drills and blasts the non-emerald containing rocks, and hydraulic shovels load the material into trucks for transport to the waste pile for dumping. The waste pile is then leveled and reforested. During our visit, we witnessed the leveling of the waste pile for pit #1.

Leveling the Ground
The earth removed from pit #1 has been placed in the area above it and is being leveled off for reforestation. Photo by Andrew Lucas/GIA.
Belmont is currently moving 900,000 tons of waste per year and so far has reforested 50 hectares (about 123 acres). Pit #1 is still being mined, but once its emerald-bearing material is fully depleted, it will be backfilled with the waste from the other pits. Once pit #1 is completely backfilled it will be reforested. That is expected to be completed in about 10 years.

Belmont has its own reforestation team. Its manager has a degree in environmental engineering. They have a nursery where they raise trees for reforestation. Belmont considers it imperative to have enough of a variety of native trees to rebuild the forest to exactly the same state it was in before mining. The Belmont crew takes on all responsibility for rebuilding the natural habitat, including checking to see that the same number of animals return to live in the reforested area that was there originally.

Reforestation
The earth being dumped from pit #1 will be leveled and the area will be reforested to look similar to the forested area in the background. Photo by Andrew Lucas/GIA.
Their methods combine environmental restoration with sound mining economics. They reduce the distance waste has to be transported by placing the pits near each other and mining the same vein. By backfilling pit #1 with the waste from the other pits, transportation costs are reduced. This also allows them to remove waste and place it in an already-mined area so they do not have to degrade virgin land. When Belmont plans mining activities, they also plan environmental protection, such as reforestation, right from the beginning. The two efforts are intimately connected. One of the biggest cost factors in mining today is environmental protection, so planning from the start to minimize environmental degradation is not only the right thing to do but also economically sound.

SORTING

Sorting begins at the processing plant, where optical sorters separate emerald-bearing from non- bearing schist. Belmont has used optical sorting since 2004. Before that, workers handpicked the emerald-bearing schist from conveyor belts. Even in the 1980s, Belmont was looking for a more automated sorting method, but they did not find the proper technology until 2004.

OPTICAL SORTING
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The optical sorters have proven to be more consistent than human sorters in finding emeralds. The original optical sorter has been completely updated with new closed circuit cameras, computers, and software. Also, they added an additional optical sorter. The original optical sorter has been optimized to sort schist that is between 2 and 10 millimeters in size and the second optical sorter from 10 to 40 millimeters in size. Both optical sorters have about a 95 percent accuracy rate for identifying emerald-bearing schist from mine ore, and are consistent from day to day and hour to hour. Belmont feels that with some further refinements to the process they will achieve 97 to 98 percent accuracy.

1981 Sorting Process
The Belmont sorting facility of 1981 was state-of-the-art for colored gemstones at the time, with conveyor belts handling different schist sizes. By 2004, however, Belmont had incorporated state-of-the-art technology in the form of an optical sorter. Courtesy Belmont mine.
Optical sorter
This is one of Belmont’s optical sorters, which find and separate emerald-bearing schist. The mine has two sorters to handle different size ranges. Photo by Andrew Lucas/GIA.
Basically, the closed circuit cameras scan schist coming through the optical sorter on a conveyor belt for emerald. When emerald-bearing schist is identified, air jets blow it off onto another conveyor belt. The newer optical sorter has stronger air jets that can blow the larger pieces of emerald-bearing schist onto the second conveyor belt.

HOW THE OPTICAL SORTER WORKS
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The capacity of the optical sorter that handles larger schist sizes is 5 to 15 tons per hour, depending on the size of the material coming through. The capacity of the optical sorter that handles smaller schist sizes is only 2 tons per hour. Belmont is preparing to add another optical sorter in the future to increase processing of the smaller schist. The material must be in a single layer in order for the cameras to recognize the presence of emerald. Since smaller schist weighs less, it operates at a lower ton-per-hour rate.

After sorting, the emerald-bearing schist is transported to Belmont’s final sorting and cutting facility in Itabira. The first step is to break away the phlogopite and often quartz to leave just the emerald crystal. Workers use pliers to break the host rock away from the emerald, then to break away any highly included areas in a process called cobbing. The rough is then ready for sorting and grading into parcels.

Cobbing
Highly included areas of the emerald crystal and remnants of the host schist are removed from the rough by cobbing with pliers. Photo by Andrew Lucas/GIA.
Belmont sorts emerald rough into categories of size, shape, color, and crystallization or clarity. There are five size classifications, and there are 10 further classifications within each size range. Shape comes into play when the rough stones are flat and will be used for marquises, baguettes, etc. These are placed in a separate group for further grading.

Sorting Emerald Rough
At their facility in Itabira, Belmont sorters sort the cobbed emerald rough into categories of size, shape, color, and clarity. Photo by Eric Welch/GIA.

THE CUTTING CENTER

Belmont has a small cutting facility that utilizes Israeli cutting machines that are modern improvements over traditional jampeg devices, where the rough gem is attached to a dop that is then inserted into a guide that allows fast adjustment of the cutting angles from facet to facet. Traditional jampegs have long been used throughout Asia. Modern improvements in the Israeli machines allow fast placement of the dop along with improved precision.

CUTTING BELMONT EMERALDS
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Belmont’s girdling and calibration machines are all hand operated, but the equipment also allows for precise calibration measurements. During our visit, they were cutting numerous emeralds into various calibrated sizes for specific jewelry mountings. Cutting is not as inexpensive in Brazil as in other parts of the world, so the cutting must be precise and of high quality. During the faceting process, the Belmont cutters constantly check the stones for symmetry and polish quality.

Green on Green查看图库
Faceting a Belmont Emerald
Girdling
Belmont’s girdling machine is used for rounds and other shapes. It can be set to fashion a stone’s measurements to within a hundredth of a millimeter. Photo by Andrew Lucas/GIA.

CUTTING THE MINE-TO-MARKET ROUGH

This, of course, was not the process used for the large stone being cut from the nearly 150-carat piece of rough we were planning to track from mine to market. This was a large, fine-quality emerald that would be cut to maximize beauty and weight recovery. Any specific measurements were meaningless compared to those two criteria, as the mounting would be custom-made to fit the stone.

CUTTING THE EMERALD
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The first step in the cutting process was to saw the stone. Marcelo equated sawing an important stone with gambling. It is very exciting, “a moment of high adrenalin.” Marcelo said, “We can get addicted to it.” He also said, regarding the sawing process, “You can go from heaven to hell or the opposite just after one sawing.”

Impressive Rough
The mine-to-market rough started out as an already-impressive crystal. Photo by Andrew Lucas/GIA.
Marcelo and Donizete had high expectations since they found the rough so “amazingly beautiful.” As Marcelo said, “We had a big fear to make a wrong decision and damage what nature made so carefully.”

After the first sawing, Marcelo told us, “We did the right thing,” and their first feeling was a kind of relief from the initial pressure. They immediately regained their excitement for the next sawing steps.

The Initial Examination查看图库
Sawing a Special Emerald
The original rough weighed 29.8 grams. Belmont’s master cutter started by cleaning it and creating windows into the gem with the grinder wheel to help with decisions on where to start sawing. Each step provided a better interior view that led to further cutting decisions. The sawing process resulted in 39 sawn pieces of cuttable rough, weighing a total of almost 134 carats.

The largest was a 40.68-carat piece of rough, which was sawn several times to get it to the desired point of clarity and quality. Its shape allowed very good weight retention, and the quality was good, so the hope was for a cut stone that was close to 50 percent of the weight of the sawn rough, a good percentage for colored stones, especially bright ones.

The Largest查看图库
Sawing Results
The sawing process revealed included problem areas in the 40.68-carat piece of rough. They were removed. The question of which of two table directions to take was settled by the last sawing, after a dark and very noticeable inclusion was removed. It was a tough choice as the saw removed weight they did not want to lose, but the dark inclusion had to be removed to yield a fine cut stone. The master cutter changed to an extremely paper-thin saw blade to allow for minimal weight loss.

Preforming
The sawn mine-to-market stone was preformed against a grinding wheel to define its shape before faceting. Photo by Andrew Lucas/GIA.
There was another included area that could have been sawn off before preforming, but the master cutter decided he would rather remove the area gradually with the grinder. Some emerald rough has internal characteristics that make it brittle and difficult to preform. This rough had good quality and was very stable during the critical preforming stage. Also, the rough itself was partially preformed by nature, with areas of the crystal already shaped like a pavilion and an area shaped for the table. The sawing process removed this advantage for some of the sawn stones but still left the some of the natural useful shape for the largest stone, our mine-to-market stone.

Taking Shape
At this stage, the emerald is beginning to look more like a finished stone. Photo by Andrew Lucas/GIA.
26.95 Carat Preform
After preforming, our mine-to-market emerald weighed 26.95 carats. Photo by Andrew Lucas/GIA.
The sawing and preforming stages helped guide the removal of significant value-lowering inclusions as well as table orientation and cutting directions. The faceting step had a strong influence on the brightness of the stone, as the exact proportions of the pavilion angle, crown angle, table percentage, and other facet placements were decided. Again, there is always a compromise with expensive rough between bringing out the best color and brightness, further reducing any visible inclusions, and creating pleasing symmetry and retaining as much of the valuable weight as possible. Through years of experience, Belmont cutters know what their customers are looking for in terms of appearance and cost per carat.

Master Cutter查看图库
Faceting the Mine-to-market Stone
During faceting, the stone was cut to maximize light return and gain attractive proportions and symmetry, with the added goal of maximizing weight yield, always a difficult blend of objectives. Some weight had to be lost to achieve a return of the beautiful green color to the eye. The pavilion of the stone had to be angled properly so there was no unsightly window where color intensity was lost, while also keeping in mind the high cost of removing every bit of weight. After the faceting was complete, the finished stone weighed 19.70 carats.

Cutting Complete
Once the stone was removed from the dop, some of the wax was still visible on the pavilion. Next, it will be cleaned, examined, and enhanced. Photo by Andrew Lucas/GIA.

IMPROVING THE STONE’S APPEARANCE

The vast majority of emeralds in the market, including very high-end emeralds, undergo clarity enhancement. This involves filling surface-reaching fissures with a colorless to near-colorless material to make them less visible. Gemstone fissures are filled with air, which makes them very visible in the stone. When a foreign material with similar optical properties to the gem material is used to fill the fissures, they become much less visible. Generally, the closer the refractive index of the colorless to near-colorless filler material is to the refractive index of the emerald, the better it conceals the fissure. A variety of oils, resins, epoxies, and polymers are used to fill fissures in emerald.

ENHANCING THE EMERALD
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For this special mine-to-market emerald, Marcelo told us the customers he has in mind prefer the use of cedarwood oil to fill the fissures. While at the Belmont sorting and cutting facility in Itabira, we witnessed the entire enhancement process.

Cedarwood Oil
Belmont uses cedarwood oil to fracture-fill their emeralds, as many of their customers request this material. Photo by Andrew Lucas/GIA.
After cleaning the fissures out with a solvent, the stone was soaked, along with a few of the other stones cut from the same rough, in a beaker full of cedarwood oil, adding heat to allow for better penetration of the oil into the emerald. This is usual practice for enhancement processes like this, where a slight amount of heat and pressure makes the oil flow more thoroughly into the fissures.

Adding Heat查看图库
Enhancing the Stone
Before enhancement, we joined the Belmont professionals in examining the emeralds. They pointed out the fissures that they hoped would be less visible after enhancement. Cutting gemstones always involves compromise. This is especially true of higher-value material. To remove the fissures during cutting would have required too much loss of weight from the rough to be economically viable. After examining the stone again, it was placed in the beaker of cedarwood oil and soaked overnight.

The next day, the emeralds were removed from the beaker and the oil was wiped off the surface and then washed with water and baby shampoo before another examination. The visibility of the fissures had lessened, but not as much as they had hoped for, so the emeralds went back into a beaker of cedarwood oil and were again soaked overnight for further enhancement. This process sometimes goes on for several days to achieve the best results.

RE-CUTTING THE STONE

After enhancement, Marcelo was still not happy with the visibility of one fissure on the pavilion. He decided to re-polish the stone slightly and remove some of the fissure, making it less visible. Re-cutting or re-polishing expensive material is always a decision that requires experience and planning. With inexpensive material, it is sometimes a matter of considering labor costs. For expensive material, it is a question of whether the gain in beauty will raise the per-carat price enough to compensate for the effects of the weight loss. There is also always an element of risk anytime a stone is re-cut.

Re-evaluating the Emeralds
After re-evaluating all the cut emeralds, from the smallest to the largest, Marcelo and his master cutter made the painful decision to slightly re-cut the mine-to-market stone to remove some of a fissure. Photo by Duncan Pay/GIA.
Emerald in particular is subject to breaking or chipping during re-cutting, more so than some other stones. In this case, a chip occurred during re-polishing of the pavilion, resulting in a reduction of weight from 19.70 carats to 18.17 carats. The stone then went through the enhancement process again and was ready to travel into the global marketplace.

When Marcelo was asked if the final largest cut stone from the rough met his initial expectations, he said “Yes, that was an amazing stone, big and beautiful. I was happy we did a good job. Fine-quality stones like that are so rare that I got jealous and possessive about it, like having a newborn baby.”

ENTERING THE GLOBAL MARKET

Marcelo and the 18.17-carat emerald arrived in New York City on Friday, April 25, at about 8:00 in the morning. After checking into his hotel, he took the stone to the GIA Laboratory in New York for a report. Marcelo felt that a gemological report would add a great deal of value when selling a large, high-quality emerald. Marcelo also showed the stone to a couple of high-end New York jewelers.

Lab Photos
Both emeralds are from the original large piece of rough. The larger one is the 18.17-carat mine-to-market stone. Both were photographed in NY while receiving their GIA Laboratory reports. Photo by GIA.

Emerald ReportVIEW GALLERY
Emerald Report
The next stop for the emerald was the June Gem and Jewelry Show in Hong Kong. At that show, it was sold to a jewelry manufacturer and retailer from Thailand. The jeweler has two retail stores in Bangkok, the first one established in 2009. He had been a jeweler for 22 years, however, and started making jewelry when he was 13 years old. Most of his clients are private collectors looking for jewelry with custom designs and unique and high-end gem materials. The company has a total of 35 employees in its two retail stores and a jewelry manufacturing factory, all in Bangkok. The owner does all the jewelry designs and supervises all the production. Most of his production is hand fabricated, with some wax carving and casting as required by the design.

His jewelry designs feature colored stones prominently and include ruby, sapphire, emerald, fancy-colored diamonds, Padparadscha sapphire, alexandrite, and other more rare materials like Melo pearls. Fancy diamond colors include shades of yellow, blue, and pink, and may be used as center stones or accent stones. Colorless diamonds are usually used as accent stones. The precious metals used in the jewelers’ pieces include 18K yellow and white gold, 22K yellow gold, 18K rose gold, and platinum.

The jeweler set our mine-to-market emerald in a 22K gold ring with wire prongs. Micro-pavé settings held six orange diamonds, five yellow diamonds, 94 pink diamonds, and 19 colorless diamonds. The deep, velvety, grass-green color of the emerald inspired the floral design. The fancy-colored diamonds add contrast and reflect the range of colors seen in flowers. The yellow, orange, and colorless diamonds represent flower petals, while the pink diamonds on gold wire represent the stems and branches. The emerald was set at an angle to create a more lively appearance.

The person who bought the ring is a regular client who likes to collect fine-quality colored stones in uniquely designed jewelry. Her design taste centers on natural and free-flowing shapes and floral designs. She also was intrigued by the Brazilian source of the emerald and the Belmont mine’s environmental practices.

This emerald, mined from an original pit of the Belmont mine near Itabira, Brazil, received a gemological lab report in New York City while it was being displayed around the NY market, and then traveled to Hong Kong, where it was purchased at a trade show by a jeweler from Thailand. The stone was then mounted in a custom-designed ring, put into the jeweler’s retail store, and sold to someone who highly appreciates unique fine jewelry, thus completing its global mine-to-market journey and eventually becoming a treasure for a consumer to enjoy.

The Finished Ring
Our magnificent emerald traveled from Brazil to NY, then to the Hong Kong Gem and Jewelry Show, and was finally set in a custom-designed ring in Bangkok, Thailand. Photo courtesy M. Suradej Joaillerie.

The Grand Sapphire of Louis XIV and The Ruspoli Sapphire

Since it was added to the French crown jewels in 1669, the 135.74 ct Grand Sapphire has been regarded as one of the world’s most magnificent sapphires. Newly discovered archives indicate that Louis XIV obtained the Grand Sapphire at about the same time he acquired the Tavernier Blue diamond; both gems were mounted in gold settings in 1672. Although the Grand Sapphire is often referred to as the “Ruspoli” sapphire, this study shows that these are, in fact, two different gems. Microscopic and spectroscopic evidence (Raman, UV-Vis-NIR absorption, and laser-induced fluorescence) suggest that the Grand Sapphire originated in the metamorphic/detrital terrain of Sri Lanka.
Among the French crown jewels, four are preeminent. The 140.62 ct Regent and the 52.23 ct Grand Sancy diamonds (Balfour, 2009) are held in the Louvre Museum. The approximately 69 ct French Blue diamond was stolen in 1792 and recut to become what is now the Hope diamond (Farges et al., 2009; Post and Farges, 2014), housed at the Smithsonian Institution’s National Museum of Natural History. The 135.74 ct Grand Sapphire, shown in figure 1, was donated to the National Museum of Natural History (MNHN) in Paris in 1796 (Morel, 1988) and has remained there ever since.

Like the Grand Sancy and French Blue diamonds, the Grand Sapphire was added to the French crown jewels during the 72-year reign of King Louis XIV (Bapst, 1889). Morel (1988) reports that the gem was purchased from a merchant named Perret, who acquired it from a German prince, who bought it from the Ruspolis, an Italian noble family. This is how the gem also became known as the Ruspoli sapphire. Morel added that it once belonged to a poor Bengali spoon merchant, explaining its other nickname, the Wooden Spoon Seller’s sapphire.

While researching the historical archives for the French Blue diamond, we found no evidence of a jeweler named Perret serving Louis XIV. In fact, no such name is found among the registries of jewelers working in 17th century Paris (Bimbenet-Privat, 2002). Furthermore, no mention of the Ruspoli family surfaced until much later (Barbot, 1858); royal sources from the 17th and 18th centuries never refer to this origin. Because the connection between the Grand Sapphire and the Ruspolis appeared questionable, we conducted a thorough study of the French National Archives in Paris, along with the city’s archives, to better understand this confusing pedigree. We also performed an on-site gemological study, using portable instruments, to determine the Grand Sapphire’s physical properties. Due to the heightened precautions surrounding the preservation of the historical gemstone, this study was conducted in a single day, in the controlled confines of the MNHN, using portable spectrometers and complementary equipment. From the measurements obtained, we propose reasoned assumptions as to the geological and geographic origin of this famous sapphire.

BACKGROUND 

The earliest dated documentation of the Grand Sapphire is the 1691 inventory of the French crown jewels (Bapst, 1889). The sapphire is described as a “violet sapphire,” “lozenge-shaped” and set in gold. Until the end of the 17th century, violet encompassed a color range from indigo blue to purple (Pastoureau, 2000). This range is consistent with the observed color, a medium blue with pale violet hues. The six-sided lozenge cut was rare for the 17th century (and even later). Its weight (“7 gros ½ et 12 grains,” equivalent to 28.74 g) is given with its gold setting. That year, the gem was appraised at 40,000 livres, the standard French currency at the time. On average, one livre in 1691 is roughly equivalent to US$15 in 2015 (based on the calculation by Allen, 2001).

In 1739, King Louis XV was inducted as a knight of the Order of the Golden Fleece (Farges et al., 2009). His jeweler, Pierre-André Jacqumin (or Jacquemin), was commissioned to create an insignia of that chivalric order. We recently discovered (Farges et al., 2008) that Jacqumin submitted two proposals: one with two main diamonds, including the French Blue (figure 2, left), and another with two large sapphires (figure 2, right). For the second version, the Grand Sapphire almost certainly would have been recut, as the king asked Jacqumin to use the existing crown jewels in the emblem (Morel, 1988). Because the king chose the diamond insignia, the sapphire was preserved, though its 1672 gold setting had disappeared: The sapphire is described without any gold setting in the 1774 royal inventory, kept in the French National Archives. Its weight is listed as 132 old Paris carats, equivalent to 135.18 ct (Morel, 1988). Like all the other jewels of the French Crown, the sapphire was kept within the Garde-Meuble (the royal storehouse), which is now the Hôtel de la Marine on Place de la Concorde in Paris. Hence, it was also known as the “saphir du Garde-Meuble.”
Two designs for Louis XV’s Order of the Golden Fleece emblem 
Figure 2. The two designs created by royal jeweler Pierre-André Jacqumin (ca. 1749) for
Louis XV’s Order of the Golden Fleece emblem. The version on the left shows the
approximately 69 ct French Blue diamond below the Côte de Bretagne, a 107.5 ct red
spinel carved as a dragon. The version on the right, adorned with two large sapphires,
probably would have entailed recutting the Grand Sapphire. Louis XV selected the first
design, though the jewel was stolen in 1792. Courtesy of the Herbert Horovitz collection.
French crystallographer Jean-Baptiste Romé de l’Isle (1772) studied the unmounted sapphire and concluded that it was a natural, uncut gem. He even classified the Grand Sapphire as the most ideal crystal form for his fifth crystallographic system, the “rhombic parallelepiped” (figure 3). In the second edition of his Crystallographie, Romé de l’Isle (1783) seemed somewhat uncertain about his 1772 conclusion, writing that the gem’s facets might be related to human polishing. But Romé de l’Isle later received two crystal models of ruby shaped like the Grand Sapphire, causing him to reassert his original hypothesis (Romé de l’Isle, 1787). That same year, Mathurin Jacques Brisson published the stone’s density (equivalent to 3.9941 g/cm3, consistent with corundum), but stated that the stone’s shape was “most likely man-faceted” (Brisson, 1787). Despite this observation, the 1789 royal inventory (also kept in the National Archives) describes the sapphire as “not cut”; no appraisal is given. In 1791, another royal inventory now housed in the National Archives (Bion et al., 1791) characterized the sapphire as “a large chunk of sapphire, lozenge, six-sided, polished flat on all its facets. Two clear edges and rounded, bright and clear, weighing 132 k 3/16.” This was equivalent to 135.88 modern metric carats, with “k” representing old Paris carats. The sapphire’s value was appraised at one hundred thousand livres, roughly equivalent to US$1.5 million in 2015.
Early drawing and ceramic model of the Grand Sapphire
Figure 3. Left: Plate IV from Romé de l’Isle’s Crystallographie (1772) shows the Grand Sapphire (number 2 in this figure). Romé de l’Isle thought that sapphire, with calcite (number 1), exhibited the primitive shape of his fifth system of crystallography, the “rhombic parallele­piped.” Right: An unglazed ceramic model of the Grand Sapphire (13 × 3 × 3 mm) made for Romé de l’Isle ca. 1770. This model, rediscovered in 2015 at the MNHN, is among the earliest ever produced. Photo by François Farges, © MNHN.
In September 1792, at the height of the French Revolution, rioters looted the royal treasury and stole most of the crown jewels, including the Regent, Grand Sancy, and French Blue diamonds. According to Morel (1988), the Grand Sapphire was not stolen. In the National Archives, however, we found an inventory completed immediately after the theft, which did not list any sapphires among the few remaining gems (Farges and Benbalagh, 2013). We therefore conclude that the sapphire also disappeared. A subsequent inventory from the Paris archives, dated December 23, 1792, contains the Grand Sapphire and other important sapphires of the French crown jewels (see box A). Presumably, these were recovered shortly after the looting, along with other notable gems, including the Peach Blossom and Hortensia diamonds (Bapst, 1889).
BOX A: THE FRENCH CROWN JEWELS SINCE THE 1792 LOOTING
Soon after the looting of the royal storehouse, a first inventory was conducted on September 21, 1792. Officials established a loss of more than 95% of the treasure inventoried a year earlier (see Bion et al., 1791). But in October 1792, several of the thieves were identified. On his way to the guillotine, a man named Depeyron confessed (in exchange for his life) where he had hidden several large gems, including the Hortensia and one of the Mazarin diamonds (Bapst, 1889). As the investigation progressed, many jewels were eventually recovered. Inventories were thus regularly compiled to demonstrate that the police were conducting an efficient investigation. This is how the Grand Sapphire of Louis XIV resurfaced in December 1792. Eventually, the Grand Sancy and Regent diamonds were discovered during the spring of 1794. The only large gem never recovered was the French Blue, which was not considered as important as the colorless diamonds.

Once most of the French crown jewels were recovered, a committee decided to contribute the pieces to various museums for the public’s benefit. Other royal collections were also dispersed, including artworks, precious books, and furniture. While jewels were assigned to the forthcoming Louvre museum, the Grand Sapphire was considered a mineral and thus went to the MNHN.

When the French Empire was established in 1804, the crown jewels were reconstructed, with new acquisitions compensating for the 1792 losses. In 1887, the French government sold off most of the treasures, and only two dozen pieces were preserved for historical purposes. Most pieces were purchased by private collectors and companies such as Tiffany. Many gems were then dismounted, recut, or altered to a more modern taste. Today, France is attempting to recover the surviving pieces as part of its cultural heritage. Since 2014, the crown jewels donated to the MNHN have been displayed in a permanent exhibit, “Treasures of the Earth.”

The Grand Sapphire was among the royal gems donated to the MNHN’s mineralogy gallery in 1796 (figure 4) for the purpose of “public education” (Morel, 1988), most likely because state officials accepted Romé de l’Isle’s belief that the sapphire was an uncut crystal. Louis Jean-Marie Daubenton, head professor of mineralogy at the MNHN, probably knew of the gem’s cut and prestigious pedigree (Morel, 1988). Indeed, his most distinguished scholar, René-Just Haüy (later regarded as the “father of modern crystallography”), soon recognized that the sapphire shape bore the “polish of art” (Haüy, 1801).
MNHN inventory, ca. 1800
Figure 4. In this official MNHN inventory, ca. 1800, the Grand Sapphire is seen in the middle row (item “a.67”). Photo by François Farges, © MNHN.
Since the sapphire’s acquisition by the museum, little has happened with it. Barbot (1858) wrote: 
The most beautiful sapphire known is oriental; it is described in the Inventory of the French crown jewels, performed in 1791; its history is quite intriguing. This sapphire, with no flaws or defects, weighs 132 1/16 carats [old Paris carats, equivalent to 135.75 modern metric carats], it has a lozenge six-sided shape and is polished flat on all its facets. It is appraised at 100,000 francs.
Then, Barbot added this previously unpublished information:
This marvelous sapphire was found in Bengal by a poor man who was selling wooden spoons, so the gem bears this nickname. Afterwards, it belonged to the Rospoli [sic] House in Rome from which it was then purchased by a Prince of Germany, who in turn sold it to Perret, a French jeweler, for 170,000 francs. This was the stone involved in the famous trial of the sapphire. Considering its qualities and its extraordinary weight, we think that this sapphire’s valuation is not properly well estimated. It is now in the Musée de Minéralogie. 
The first excerpt clearly refers to the Grand Sapphire. In the second excerpt, Barbot is the first to mention the sapphire’s previous owners, including the Bengali spoon seller, the Ruspolis (an Italian noble family misspelled by Barbot), a German prince, and finally Perret. Barbot also refers to “the famous trial” in which the gem was supposedly involved (which will be discussed at greater length). Since then, the Grand Sapphire has often been referred to as the “Ruspoli” (Simonin, 1867) or the Wooden Spoon Seller’s sapphire (Snively, 1872; Streeter, 1877; Tagore, 1879). The many inconsistencies in the gem’s narrative prompted us to reexamine those references, in order to better understand the historical, geographical, and geological origins of this extraordinary gem.

MATERIALS AND METHODS

Archives. We extensively investigated a series of unpublished documents uncovered in various locations, including the MNHN, the National Archives, the Paris city and departmental archives (Archives municipales and départementales), and the archives at the École Militaire and the National Library of France (BnF), all in Paris. We have also reviewed the diplomatic archives of the French Foreign Ministry in La Courneuve. This last search included the recently discovered books of royal gemstones (Livres des Pierreries du Roi), consisting of dozens of volumes produced between 1669 and 1789 and containing thousands of pages of unpublished information.

On-Site Experiments. Weight, goniometric, microscopic, and spectroscopic testing was conducted using portable instruments, as the sapphire was not allowed to leave the museum. These miniature instruments are well suited for examining highly valuable or oversized artifacts that cannot be transferred from the museum to a regular laboratory. The main limitation of portable instruments is their reduced specifications (low energy output, lateral resolution, and signal-to-noise ratio, among others) compared to larger versions of these instruments.

The analyses included Raman scattering spectroscopy using an Ocean Optics QE 65000 spectro­meter, with 532 and 785 nm excitation lasers; near-ultraviolet to near-infrared (UV-Vis-NIR) spectroscopy with an Ocean Optics USB2000 spectro­meter, covering a 350–1000 nm range with a spectral resolution of 1.5 nm (FWHM), using a tungsten lamp; and photoluminescence spectroscopy, induced by either a UV lamp (365 nm) or a continuous green laser operating at 532 nm excitation, all at ambient temperature. The fluorescence emission was collected with an optical fiber and analyzed by the Ocean Optics USB2000 spectrometer described previously (Panczer et al., 2013), using a UV lamp as the excitation source (254 and 365 nm, 6 W each). We also used a Marie Putois and Rochelle contact goniometer (from 1794), a binocular microscope (Krüss KSW4000 with 10× and 30× magnification), a Krüss GMKR10 professional refractometer with an LED source, and a Krüss GMKR13 polariscope.

Off-Site Experiments. For the items allowed to leave the exhibition gallery, such as the replica described below, 3-D laser scanning was performed at MNHN’s Surfaçus facility using a Konica Minolta Range 7 operating with a 660 nm laser (accurate to approximately 4 µm). Scanned data were reduced (edge-collapse decimation) using MeshLab, GemCad, and DiamCalc software packages for final adjustments of facets. Chemical analyses were performed with an SD3 Bruker solid-state X-ray detector (133 eV resolution) installed in a Tescan Vega II LSU scanning electron microscope operated in low-pressure mode (20 Pa) at 20 kV.

RESULTS AND DISCUSSION

The “Trial of the Sapphire.” In our archival search for a jeweler named Perret who might be involved in the story of the Grand Sapphire, only one match was found, from a trial conducted between 1811 and 1813 (Méjan, 1811; Berryer, 1839). A few months before the trial, Jean-François Perret purchased a large sapphire that allegedly once belonged to the Ruspoli family. He sold the gem to Milanese jeweler Antonio Fusi, who paid a deposit. A few days after this transaction, Fusi tried to cancel the sale and have his deposit refunded, but Perret refused. After the two-year trial, Fusi was ordered to pay Perret the balance due. To satisfy the judgment, the court seized the sapphire and sold it at auction in December 1813 (“Le procès du saphir,” 1813).

At the time of this trial, the Grand Sapphire had been kept at the MNHN for nearly 20 years. We found no evidence showing that this gem was sold by the MNHN before the trial and recovered later. Therefore, those pieces of information are contradictory. But Pierre-Nicolas Berryer, the lawyer who represented Perret, described this sapphire involved in the 1811–1813 trial as “of the purest sky blue, with an oval shape with symmetrical facets … much more magnificent than the well-known one of the royal storehouse; unique for its kind, it was priceless” (Berryer, 1839).

While Berryer failed to mention the gem’s weight, a legal expert named Maurice Méjan published an 1811 summary of recent trials, including that of the sapphire. Fortunately, Méjan recorded its weight as 133 old Paris carats (equivalent to 136.9 modern carats). Regardless, the shape and cut given by Berryer are not consistent with the Grand Sapphire. Notice, too, that Berryer compares the sapphire to one from “the royal storehouse,” the well-documented nickname of the Grand Sapphire prior to the 1792 looting (Farges and Dubois, 2013). In other words, Berryer considered the Grand Sapphire and the Ruspoli sapphire two distinct stones.

The Real Ruspoli Sapphire Rediscovered. In 2013, during a search of the National Library in Paris, we found a leaflet connected to the December 1813 court-ordered auction (inventory number SZ-1350). The leaflet claims that the sapphire was owned by a poor Bengali wooden spoon seller, the Ruspolis, and even Charlemagne, “who is believed to have received the gem from an Indian prince.” Yet there is no evidence within the document to support any of this. Therefore, we are skeptical of any historical provenance published in this leaflet, including the association with the Ruspoli family, and consider it the seller’s attempt to influence the price.

The auction leaflet shows a drawing of the sapphire involved in the trial (figure 5A). This drawing had to accurately represent the gem, which was on public display at the Hôtel Bullion in Paris a few weeks before the sale (“Le procès du saphir,” 1813). The stone depicted has a square cushion shape with rounded corners, brilliant faceting on the crown, and a step-cut pavilion. This drawing does not even remotely resemble the Grand Sapphire, but it does match Berryer’s 1839 description of the sapphire from the trial. The weight of this gem (136.9 ct when converted to metric carats) is close, but not identical, to that of the Grand Sapphire (135.74 ct). Therefore, the gem attributed to the Ruspolis in the auction leaflet is not the Grand Sapphire. Barbot clearly confused them in his 1858 treatise. How did this happen?
Illustrations and a historical replica of the Ruspoli sapphire
Figure 5. Images of the Ruspoli sapphire. A: An illustration from the 1813 auction leaflet for the gem, © Bibliothèque National de France. B: The top row shows the historical replica of the Ruspoli sapphire, ca. 1830 (30 × 29 × 15 mm; MNHN inventory number 50.167). The bottom row shows the laser-scanned 3-D model after edge-collapse decimation, © MNHN. C: A drawing from Hertz (1839) of H.P. Hope’s largest sapphire (private collection). Photos by François Farges.
In 2012, we found a blue glass replica of a large gemstone in the MNHN drawers. Inventoried as no. 50.167, the replica is composed of a potassic lead glass (“strass”), according to SEM/EDX data, and doped with minor amounts of cobalt (approximately 0.2 wt.% CoO) that account for its vivid blue color. The 3-D model for this replica, obtained through laser scanning, is similar to the drawing of the Ruspoli sapphire (figure 5B, bottom). Its volume corresponds to a sapphire weighing 163 ct. The MNHN inventory, dated 1850 (but donated much earlier; see Farges et al., 2009), states:
Inv. no.
(18)50.167
Origin
Mr. Achard
Description
Model in strass of a very
nice sapphire belonging
to Mr. Hoppe, and sold
by Mr. Achard
Location
Technological
showcase
No. 9
“Mr. Achard” is most likely David Achard, a Parisian jeweler from 1807 to 1831, who also donated the lead casts of the French Blue (MNHN inventory number 50.165) and another diamond (MNHN inventory number 50.166). Haüy (1817) named Achard the leading Parisian lapidary and jeweler. “Mr. Hoppe of London” is none other than Henry Philip Hope, for whom the Hope diamond is named (Farges et al., 2009).

The sale of the sapphire to Hope is confirmed by his catalogue of gems, compiled in 1839 by Bram Hertz, a prominent London jeweler. This inventory confirms the MNHN records: the drawing of his largest sapphire (figure 5C) is identical to the glass replica (MNHN inventory number 50.167; figure 5B). Also, Hertz’s 1839 drawing closely resembles the one from the 1813 auction leaflet (compare figures 5A and 5C). Furthermore, their weights correspond exactly with 532 grains (equivalent to 136.9 ct). Therefore, it would seem that Achard purchased the sapphire sometime after the 1813 auction and, before his death in 1831, sold the stone to Hope. At some point during this period, Achard donated the replica to the MNHN, where it was exhibited next to the Grand Sapphire in the same “Technological showcase No. 9” (described in Hugard, 1855). Our hypothesis is that Barbot examined both stones while visiting the MNHN’s gallery of mineralogy and confused them in his book.

Hertz (1839) describes Hope’s sapphire, now identified as the Ruspoli, as
A very large and fine sapphire, of a square shape with rounded corners, and of a very fine velvet-blue colour, resembling the flower of the bluebottle found among the corn. It is of the purest and of a most charming hue, having, moreover, the advantage of displaying its beautiful colour equally as fine by candle as by day-light, a quality which is rarely met with in a sapphire. It is very finely cut, and shows an extraordinary refulgence…This beautiful sapphire is set as a medallion, surrounded by 23 fine large brilliants, averaging three grains each: it is kept in the 16th drawer—Wide plate 10… 532 grains.
The drawer mentioned above refers to a cabinet in which Hope stored his gem collection. The “wide plates” are a set of drawings for the most important gems from the collection, published by Hertz (1839) as an appendix to his inventory. Inside the tenth plate is the drawing of the sapphire (reproduced within figure 5C). Note that in Méjan (1811) and Hertz (1839), the weight of the sapphire remains unchanged at 532 grains, even though Paris and London used different units at the time. In other words, during his inventory of Hope’s largest sapphire, Hertz simply repeated the French weight from 1811 without reweighing it in London units.

Later Whereabouts of the Ruspoli Sapphire. Emanuel (1867) wrote that “in the Russian treasury are some [sapphires] of an enormous size, amongst them one of a light-blue tint, which formerly was in the possession of the late Mr. Hope.” Emanuel is most likely referring to the Ruspoli, easily the largest sapphire in Hope’s collection (Hertz, 1839). A portrait of Empress Marie Fyodorovna of Russia, housed at the Irkutsk Regional Art Museum, shows an impressive set of sapphire jewels. Among them is a squared sapphire in the center that could be the Ruspoli. Later, the stone was reset as the centerpiece of a sapphire and diamond kokoshnik (a Russian headdress) created by Cartier in 1909 and owned by the Grand Duchess Maria Pavlovna of Russia (Munn, 2001). The kokoshnik later belonged to Queen Marie of Romania (figure 6) and her daughter Ileana. The latter revealed that she sold the headpiece to a famous jeweler in New York around 1950 (Ileana, 1951) but did not give additional details on that transaction. Thus, the recent whereabouts of this kokoshnik and the Ruspoli sapphire are unknown. Although Ileana wrote that the sapphire weighed 124 ct, other sources indicate 137.2 ct (Munn, 2001) or even 137 ct (Nadelhoffer, 2007), values that closely correspond with the Ruspoli (136.9 ct).
Portrait of Queen Marie of Romania
Figure 6. In this portrait by Philip Alexius de Laszlo, Queen Marie of Romania is wearing the 1909 Cartier kokoshnikthat most likely bears the Ruspoli sapphire as the center gem. Examination of a high-definition image of that jewel (courtesy of Cartier archives) confirms this. Courtesy of Peles National Museum.

THE TRUE STORY OF THE GRAND SAPPHIRE 

Supposedly purchased by Francesco-Maria Ruspoli (1672–1731; see Morel, 1988), the Ruspoli sapphire has a double series of crown facets that is more typical of the late 18th and early 19th century (Schrauf, 1869). In fact, there is no proof that this gem ever belonged to the Ruspolis, as jewelers and auction sellers often contrived aristocratic pedigrees and curse legends to increase gem values. Examples include the fake Spanish pedigree of the Wittelsbach Blue diamond (Dröschel et al., 2008) or the “curse” of the Hope diamond (Post and Farges, 2014). Charlemagne’s purchase of the Ruspoli sapphire from an Indian prince appears to be another such legend. Therefore, the name “Ruspoli” is highly questionable. A more accurate alternative would be the “Achard-Hope sapphire,” as this name is related to important personages actually involved with this historical gem.

For its part, the MNHN officially denies custody of the Ruspoli sapphire, claiming instead the Grand Sapphire of Louis XIV, the companion stone of the French Blue diamond.

The Acquisition of the Grand Sapphire. We searched the French royal archives to determine the exact provenance of the Grand Sapphire. In the Clairambault collection of the National Library of France, we discovered an unpublished financial record of royal expenses for gemstones, dated 1683. It lists a lozenge-cut sapphire worth 40,000 livres (see Farges and Benbalagh, 2013). This description is identical to the one given in the 1691 inventory for the Grand Sapphire. Because no other sapphire with such a shape and value is known, we conclude that this document deals with the acquisition of the Grand Sapphire. The 1683 record also provides a new piece of information: “the sapphire is not included in the purchases,” meaning that of all gemstones acquired by Louis XIV between 1661 and 1683, this is the only one for which no money was spent. Some pagination details in this archive (see Farges and Benbalagh, 2013) suggest that the acquisition was acknowledged during the spring or summer of 1669, but we do not know its exact circumstances.

Based on these dates, we examined the French Foreign Ministry archives, where the records of the royal gemstones are kept. Newly revealed documents for 1669 (French diplomatic archives, inventory number 2040) show that the Grand Sapphire was among the faceted sapphires inventoried by the royal treasurer on July 1, 1669 (Farges and Benbalagh, 2013). Here again, no information is given on the gem’s provenance. The inventory states that Jean Pittan the Younger, the king’s jeweler, was responsible for setting the sapphire in gold. Another record from the same archives, dated August 20, 1672, reports that the setting was completed and the sapphire was returned by Pittan. The weight of the jewel is listed as “7 gros ½ et 12 grains” (28.74 g), the same weight as in the 1691 inventory of the French crown jewels. Based on the current weight of the Grand Sapphire (135.75 ct), we estimate the weight of the pure gold setting to be around two grams. This is a curiously small amount of gold for such a large stone. The most plausible interpretation is that the Grand Sapphire was set on a stand composed of gold filigree, a style favored by Louis XIV (Bimbenet-Privat, 2002, 2003). Because of its mechanical properties, such an intricate network of gold wires could support the weight of a relatively large and heavy sapphire, despite the low weight of the metal itself.

We found nothing in those archives that explains how the sapphire was obtained other than the words “not included in the purchases.” This could mean a gift, plunder, inheritance, or deferred payment. We investigated these various possibilities (see Farges and Benbalagh, 2013) with no success. Since that study, one of the authors rediscovered the 1666 inventory of the French crown jewels (Farges, 2014a). This extensive manuscript does present important new information about the jewels, but none concerning the Grand Sapphire, suggesting that it had not yet entered the royal collection. Furthermore, nothing in the 1666 bequest of the Dowager Queen Anne of Austria or the record of the Russian diplomatic visit in 1668 provided fruitful hints. Also, there is no evidence of any gem purchase by Louis XIV between 1666 and February 1669, when gem merchants Jean-Baptiste Tavernier and David Bazeu (or Bazu) returned from their voyages to India (Morel, 1988). As the sapphire is not listed among the gems purchased from those merchants, the Grand Sapphire must have been obtained shortly after their return from India, but before its official recording in the royal books—in other words, between February and June 1669.

Analogies with the Tavernier Blue Diamond. Figure 7 shows the Grand Sapphire next to a cubic zirconia replica of the Tavernier Blue diamond that was cut and donated to the MNHN by Scott Sucher (see Sucher, 2009). The similarities between the Grand Sapphire and the Tavernier Blue, both acquired in 1669, are striking. They have roughly the same dimensions. The simple cuts and faceting allow the observer to easily study their purity, inclusions, and color (Farges, 2010).
The Grand Sapphire and a replica of the Tavernier Blue diamond
Figure 7. The Grand Sapphire (left) and a cubic zirconia replica of the Tavernier Blue diamond (right). Photo by François Farges, © MNHN.
According to Zemel (2015), the Grand Sapphire is a Mogul-cut gem, like the Tavernier Blue diamond. Mogul-cut gems are often faceted irregularly or asymmetrically, usually showing a large flat base and an array of radial facets, as in the Orlov and Taj-i-Mah diamonds. Other Mogul cuts include more symmetrical shapes such as pendeloques or tables (the Darya-i-Noor diamond, for instance). Those diamonds were faceted in India during the 17th and 18th centuries, and cutters there were expert in minimizing weight loss during polishing (Tavernier, 1676). Louis XIV decided to recut the asymmetrical Tavernier Blue as an apparently symmetrical brilliant; the resulting stone became known as the French Blue. Clearly, the sapphire was already symmetrical, but the king did not ask for more ornate recutting (for instance, as a cushion with a step cut on its pavilion). If the Grand Sapphire is a Mogul cut, then either Tavernier or Bazeu must have donated it, as they were the only merchants to return from India in 1669 with gemstones (Morel, 1988). While Tavernier sold diamonds to Louis XIV, Bazeu also traded magnificent pearls and several colored gems, including two yellow sapphires and a red spinel, the latter also cut as a lozenge (Morel, 1988).

Despite the assertions of Morel (1988), Louis XIV never wore the Grand Sapphire or the Tavernier Blue diamond (Farges and Benbalagh, 2013). Instead, the gems were kept in a gold chest adorned with elaborate filigree, a masterpiece created for the king by Jacob Blanck, a little-known jeweler who worked for Jean Pittan the Younger (Bimbenet-Privat and Pié, 2014). Blanck’s creation is now known as the Louis XIV gemstone chest (“coffre des pierreries de Louis XIV,” inventory number MS 159). Bimbenet-Privat and Pié (2014) showed that the king used the chest to display his gemstones and royal ornaments to prestigious visitors, just as the Mogul emperor Aurangzeb had with Tavernier in 1665 (Tavernier, 1676).

The acquisition of two large blue gems at about the same time (the spring of 1669) is no coincidence. Around 1672, both gems were set into gold, which was out of the ordinary for the French Court. In fact, most of the diamonds in the French crown jewels were set in silver-plated gold, which was considered more valuable at the time (Bimbenet-Privat, 2002). Therefore, the setting of both blue gems into gold is atypical of this period and could be a reference to the “azure and gold” colors of the French monarchy (Pastoureau, 2000).

GEMOLOGICAL STUDY 

We used the following orientation to identify the facets of the sapphire (again, see figure 1). “Top” is the upper horizontal, nearly square facet. “Front left” and “front right” are the two main frontal facets seen in figure 1, while the left rear, right rear, and bottom facets are not visible. There is a missing corner on the upper rear area of the sapphire, at the junction of the left rear, right rear, and top facets.

Visual examination of the Grand Sapphire shows that its blue color is not uniform; rather, it displays chevron-pattern zoning. The observed color is a medium blue with pale violet hues ranging from violetish blue to pure blue, with a medium to medium-dark tone and a strong saturation. The gem reveals abundant evidence of rough handling, containing many scratches, nicks, and pits. It weighs 27.148 grams (135.74 ct).

Shape. The dihedral angles of the Grand Sapphire rhomboid are 75°, 90°, and 71°. Its shape has nothing in common with a rhombohedron (whose dihedral angles are 75.5 or 76°). The shape is a parallelepiped, with two axes intersecting at oblique angles and a third orthogonal to the two other axes. Four edges are slightly recut, connecting the three front facets seen in figure 1 (as well as another edge on the upper left rear), while the other eight edges are actually quite sharp. On the upper rear, one significant missing corner shows a flat surface of a few square millimeters (figure 8A). This surface forms angles of 105°, 85°, and 105° with its three neighboring facets. The texture of this surface contrasts with the other facets of the gem. Closer microscopic examination reveals many imperfections such as micron-size cavities around approximately circular frosted areas that are much duller (figure 8A). Also, this surface lacks crystalline patterns such as the terraces that are typical of the naturally formed crystal habit of sapphire (see figures 8B and 8C). The irregularities observed suggest some abrasive polishing by water action. This might indicate that the Grand Sapphire was recut from a larger piece of sapphire found in weathered alluvial gravels, typical of corundum in Sri Lanka (see, among others, Hughes, 1997). If the Mogul origin of this faceting is confirmed (see Zemel, 2015), one can speculate that this rough was only slightly larger than the cut gem (see Tavernier, 1676), confirming Haüy’s observation (1801) that the sapphire was cut “to preserve its volume as much as possible.”
Gemological study of the Grand Sapphire
Figure 8. A: Detail of the natural, uncut surface on the Grand Sapphire. B: A doubly
terminated gem sapphire monocrystal from the Monaragala district, Sri Lanka (45 × 11
× 12 mm; MNHN inventory number 195.146). C: Detail of the Sri Lankan sapphire’s surface,
showing crystal growth terraces. D: Two “opposite” views of the Grand Sapphire examined
under a polariscope and oriented slightly off the c-axis (shown in dark blue).
E: Three-dimensional reconstruction showing the probable location of the Grand Sapphire
within a hypothetical trigonal/hexagonal corundum crystal. Photos by François Farges,
© MNHN.
Orientation. A plane polariscope was used to better observe the chevron-patterned zoning of the Grand Sapphire (figure 8D). These chevrons correspond to the growth pattern of two of the six facet planes of the hexagonal corundum crystal (i.e., the m-planes of the hexagonal lattice system of the trigonal crystal system: [1100], [0110], [1010], [1100], [0110], and [1010]). Using the polariscope, the direction of the c-axis was determined thanks to its total extinction (sapphire is uniaxial negative). The color zoning appeared in high contrast when set 15–20° off-axis. In the pictures taken from this direction (figure 8D), the apparent angle of the chevrons is approximately 125° (close to the theoretical value of 120° for a trigonal/hexagonal crystal-like sapphire). This confirms the previous determination of the crystal orientation using the polariscope. Otherwise, the apparent angle would be much larger from other viewing angles and the chevrons would not be visible when the viewing angle was too far from the c-axis. Using GemCad, we created a 3-D model of the Grand Sapphire based on direct goniometric measurements. This model is set in an orientated hexagonal preform (figure 8E) to illustrate how the gem represented a small portion of the original crystal (assuming it crystallized isotropically) before it was smoothed by erosion.

Refraction. The Grand Sapphire’s refractive indices are 1.772 (nω) and 1.764 (nε). The gem is uniaxial negative, with a birefringence of 0.008. These values are consistent with corundum (see Bariand and Poirot, 1985).

Inclusions. We observed oriented rutile needles (figure 9) and a globe-shaped opaque black inclusion with highly reflective surfaces and a high refractive index. The opaque black inclusion resembles an iron oxide such as hematite or ilmenite.
Inclusions in the Grand Sapphire 
Figure 9. Inclusions in the Grand Sapphire, observed from the top facet (A) and the right
rear facet (B). Rutile needles and a large hematite-like inclusion are visible from both facets.
Photos by Gérard Panczer, © MNHN; field of view 1.35 mm.
Fluorescence. The Grand Sapphire showed moderate red fluorescence under long-wave UV (365 nm) illumination, but weaker fluorescence under short-wave UV (254 nm). Moreover, its fluorescence was a more intense red along the green 532 nm laser beam through the stone (figure 10).
Fluorescence reaction of the Grand Sapphire
Figure 10. Fluorescence of the Grand Sapphire. A and B: Before and after illumination with long-wave UV (red fluorescence). C and D: Before and after exposure to 532 nm laser excitation results in a strong red fluorescence along the laser beam. Photos by François Farges, © MNHN.
Raman Scattering Spectroscopy. Raman spectra collected with 532 and 785 nm laser excitation were comparable (figure 11). With 785 nm excitation, the baseline was not uniform, most likely due to the gem’s fluorescence in the Raman range (Panczer et al., 2012). In both cases, clearly detected Raman scattering peaks corresponded to their associated vibration modes (Al-O bonds in a six-fold octahedral coordination).
Raman scattering spectra for the Grand Sapphire
Figure 11. Raman scattering spectra for the Grand Sapphire, with laser excitation at
532 nm (green curve) and 785 nm (red curve). The peaks are indicative of octahedrally
coordinated Al.
UV-Vis-NIR Spectroscopy. Three zones of the gem were selected for UV-Vis-NIR spectroscopy (figure 12). One zone corresponded to the central part of the sapphire. The second and third zones had the highest and lowest color saturation, respectively. The spectra for the three zones were comparable. An absorption band was detected in the green to red spectral range for all zones, with a maximum centered near 576 nm. A more narrow absorption contribution, though less intense, was observed near 450 nm. Also, a negative-intensity line corresponded to an emission peak at 694 nm (again, see figure 12).
Unpolarized UV-Vis-NIR absorption spectra of the Grand Sapphire
Figure 12. Unpolarized UV-Vis-NIR absorption spectra (with the hexagonal unit cell shown
as a, b, and c vectors) for three different zones of the front right facet show variation in the
intensity of blue color.
Luminescence Spectroscopy. Luminescence spectroscopy, induced by either a 365 nm UV source or by a 532 nm continuous laser, showed a sharp, intense emission line at 694 nm (figure 13). This phenomenon indicated that the two wavelengths excited an extrinsic luminescent center whose electrons were subjected to a radiative transition—in this case, the presence of Cr3+atoms. The portable apparatus used did not discriminate between the transitions related to Cr3+(referred to here as R1 and R2, centered at 692.9 and 694.3 nm, respectively; Gaft et al., 2015). The other weak bands observed in the spectra are secondary peaks related to the main doublet (Panczer et al., 2013). These results also explain the negative absorption measured by UV-Vis-NIR spectroscopy near 694 nm, as seen in figure 12. 
Luminescence spectra for the Grand Sapphire
Figure 13. Luminescence spectra for the Grand Sapphire with excitation by a 532 nm
laser (green curve) and a 365 nm UV source (purple curve, with intensity doubled for
comparison with the green spectrum). The 532 nm line corresponds to the laser scattering.
Interpretation. Despite the use of portable instruments with lower resolution than laboratory or synchrotron-based instruments, the gem shows the physical properties of a sapphire. Its Raman scattering spectrum (again, see figure 11) matched that for corundum from the RRUFF database. The rutile inclusions were not weathered or dissolved. Therefore, the Grand Sapphire did not undergo any thermal treatment above 1600°C. Its optical absorption showed a maximum at 576 nm, consistent with an electron exchange between Fe2++ Ti4+ and Fe3++ Ti3+ (Ferguson and Fielding, 1971; Fritsch and Rossman, 1988). The 694 nm “negative” absorption peak seen in figures 12 and 13 was related to the presence of Cr3+ substituting for six-fold coordinated Al3+(high crystal field) in corundum (Gaft et al., 2005; Panczer et al., 2012) and was responsible for the narrow and intense red emission. Cr3+ is a frequent impurity in corundum, including sapphires (Bariand and Poirot, 1985).

Geological and Geographical Origins. Determining the geologic or geographic origin of sapphire remains a challenge even with advanced analytical methods (Mumme, 1988; Notari and Grobon, 2002; Shigley et al., 2010). For instance, blue sapphires from Sri Lanka and Madagascar show similar mineralogical and gemological properties (Gübelin Gem Lab, 2006). However, the determination of geographical origin of a rare historical gemstone such as the Grand Sapphire is based on limited but convergent criteria (inclusions, growth zones, absorption patterns, lumi­nescence, and the like). In addition, the number of possible geographical occurrences for the Grand Sapphire is historically limited: The only active deposits before 1669 were in modern-day Myanmar, Sri Lanka, and Thailand-Cambodia. The rutile inclusions observed in Burmese sapphires are usually shorter and more densely packed (see Hughes, 1997) than those observed in the Grand Sapphire, which appear more typical of Sri Lanka (L. Thoresen, pers. comm., 2015).

According to the Gübelin Gem Lab (2006), the Grand Sapphire’s UV-Vis-NIR spectrum is typical of sapphires that crystallized in metamorphic rocks. Their absorption is dominated by an intense Fe2+/Ti4+ charge transfer, with absorption maxima centered at 575 and 700 nm. The absorption bands related to Fe3+ are usually weaker (Hughes, 1997). Therefore, the Grand Sapphire probably originated from the charnokitic series (an orthopyroxene-bearing metamorphic rock with granitic composition) of Sri Lanka or their fragmented clastic (detrital) sediments, as suggested by the examination of the small natural, uncut facet of the Grand Sapphire. The use of a laboratory UV-Vis-NIR apparatus should not affect the conclusions drawn from luminescence spectroscopy, as the charge transfer bands of interest are well probed with sufficient resolution by the portable apparatus. This study therefore shows how portable instruments, despite their intrinsic limitations, can assist with the examination of museum pieces that cannot be transferred to a laboratory setting.
Timeline of Five Famous French Gems
Timeline of Five Famous French Gems

CONCLUSION 

Through a historical and gemological study of the Grand Sapphire, we have rediscovered some of its lost secrets. The stone is likely from Ceylon, present-day Sri Lanka. It may have been cut originally by Indian lapidaries (Zemel, 2015) before being purchased by a European (possibly David Bazeu) and given to Louis XIV around 1669, about the same time the monarch purchased the Tavernier Blue diamond. Both gems were set in gold under the supervision of jeweler Jean Pittan the Younger at about the same time (1672–1673). A gold setting was used, possibly to highlight the “azure and gold” colors of the French monarchy (Farges, 2010; Post and Farges, 2014). There is no evidence that Louis XIV ever wore those gems as part of his regalia. Instead, the gems were placed in a remarkable gold chest that was exhibited to impress selected visitors (see Farges, 2010; Bimbenet-Privat and Pié, 2014: Post and Farges, 2014).

The faceting of the Grand Sapphire is relatively simple but remarkable nonetheless. Recutting it as a cushion would have resulted in significant weight loss with no dramatic increase in brilliance. In this regard, Louis XIV proved to have eclectic tastes, collecting both minimally faceted (possibly Mogul) gems such as the Grand Sapphire and complex brilliant-cut faceted gems such as the French Blue, one of the first brilliant-cut diamonds ever documented (Farges, 2014b).

In 1739, the sapphire was removed from its gold setting, most likely to consider recutting it into two stones for Louis XV’s Order of the Golden Fleece insignia. Fortunately, this idea was eventually abandoned. Sometime between 1739 and 1774, the Grand Sapphire became an object of scientific study; M.J. Brisson measured its density, while Jean-Baptiste Romé de L’Isle examined its shape and eventually concluded that it was an uncut crystal. From the crystal, Romé de L’Isle shaped a model in bisque (1772). Apparently stolen in September 1792 and recovered a few months later, the sapphire entered the national collection of mineralogy at the MNHN in Paris, where Haüy (1801) once again identified it as a faceted gem.

Since 1858, the Grand Sapphire has often been confused with another gem, known as the Ruspoli sapphire, for which the MNHN possesses a historical replica that was once exhibited near the Grand Sapphire. The stones have approximately the same weight, but their faceting is dramatically different. Whereas the Grand Sapphire is a six-sided “lozenge” cut, the Ruspoli is a more conventional cushion cut. This sapphire was then sold at an auction in 1813 and acquired by the French jeweler David Achard, who subsequently sold it to Henry Philip Hope. Czar Nicholas I is said to have obtained the stone, which may have adorned a great Russian kokoshnik designed in 1909 by Cartier. Princess Ileana of Romania sold the piece to a jeweler in the United States in the 1950s, and its current whereabouts are unknown.

Unearthing elements of the true story of the Grand Sapphire reaffirms its rightful standing as one of the most important gemstones of the 17th century. Its unusual shape makes it one of the singular cut stones of all time. It is celebrated in a permanent exhibit named “Treasures of the Earth” (Trésors de la Terre), which opened in December 2014 at the MNHN. This exhibit places the sapphire in its appropriate context with the other magnificent gems and art objects of the French crown jewels.