OS GARIMPOS DE ESMERALDAS

Há sistemas de iluminação, de ventilação e de comunicação que ligam a entrada ao fundo do poço. As minas funcionam 24 horas diárias.

              

          

Marcos Nogueira

Para se chegar a um veio de esmeraldas, é preciso cavar buracos verticais com até 500 metros de profundidade no solo rochoso. Os garimpeiros passam dias a fio dentro dessas minas, dotadas de uma estrutura rústica, mas eficiente. Há sistemas de iluminação, de ventilação e de comunicação que ligam a entrada ao fundo do poço. As minas funcionam 24 horas diárias.
Os trabalhadores manipulam dinamite, respiram fuligem o tempo todo, urinam e defecam em sacos plásticos e estão sujeitos a desabamentos. O risco de morrer é real, mas pode compensar: uma gema de boa qualidade com 1 quilate (2 gramas) é vendida por até 5 mil dólares.
No Brasil, uma das principais áreas de extração de esmeraldas fica na serra da Carnaíba, Bahia, onde o mineral foi descoberto em 1 963. Lá as minas são cavadas dentro de barracões cobertos, sendo invisíveis para quem anda nas ruas do garimpo. Sob a terra, o cenário lembra um formigueiro. Para iniciar a perfuração de uma mina, é preciso instalar bananas de dinamite em fendas feitas com uma britadeira. À medida que se encontram veios de pedra preciosa e a rocha fica mais solta, os garimpeiros se valem de ferramentas mais “delicadas”, como marretas e picaretas. Isolados do resto do mundo, os caçadores de esmeraldas desenvolveram um vocabulário peculiar (leia quadro abaixo).
As primeiras esmeraldas foram descobertas há cerca de 5 mil anos, no Egito. A pedra verde é considerada a quinta gema mais valiosa do mundo – perde apenas para o diamante, o rubi, a alexandrita e a safira. A cor de uma esmeralda varia do um verde pálido ao verde intenso, com tonalidades azuladas ou amareladas. A qualidade da gema depende, fundamentalmente, dessa cor. As mais valiosas e raras são aquelas que têm verde intenso, puro ou com ligeira tonalidade amarelada. O grau de transparência e a presença de rachaduras também influem na avaliação de uma gema.
Fábio Lamachia Carvalho (autor do livro Sonho Verde, sobre sua experiência como garimpeiro)

Imagem: thisisbossi/Wikimedia Commons

TERRA DE NINGUÉM

No subsolo, os territórios de cada garimpo não são muito bem definidos. Não existe propriedade da terra. É comum que escavações de minas concorrentes acabem se encontrando

FURO N’ÁGUA

Quando o poço rompe um lençol freático, a água escorre pela parede e se acumula no fundo. É preciso, então, cavar um desvio e abrir um túnel paralelo. Para que a mina não se inunde, os garimpeiros drenam constantemente a água empoçada

LUZ NO FIM DO TÚNEL

Os túneis têm cerca de 2 metros de altura. O ar é bombeado da superfície até o fundo da mina. A fiação também desce para possibilitar a iluminação das galerias

CONTRA DESABAMENTOS

Às vezes é necessário escorar as paredes com “caixas”, ou estruturas de madeira, para prevenir desabamentos. Os garimpeiros usam a marreta para avaliar a segurança do teto: dependendo do som da pancada, a pedra está solta ou segura

Brasil e Japão na Bahia

Conheça um pouco das estranhas gírias do garimpo

Brasil – a superfície
Japão – o fundo da mina
Malado – quem ganhou muito dinheiro
Massegueiro – ladrão de esmeraldas
Boi – rocha pendurada no teto ou nas paredes da galeria
Canga – boi de xisto com pedras preciosas incrustadas
Indianada – pedras de qualidade inferior, que são vendidas para o mercado indiano
Martelete – tipo de britadeira
Quarta-feira – marreta muito grande e pesada. Tem esse nome porque poucos conseguem operá-la por mais de dois dias seguidos. Ou seja: o garimpeiro agüenta o trabalho na segunda e na terça, mas na quarta já não dá conta do serviço
Vazar – encontrar esmeraldas

O buraco é mais embaixo

Como funciona uma mina de esmeraldas na Bahia

REPESCAGEM

No entulho retirado das escavações, sempre há esmeraldas pequenas e de pouco valor. Isso atrai os “quijilas”, nome dado a quem aproveita os restos do garimpo. Geralmente são crianças, mulheres ou idosos

O ASCENRISTA

Quem controla o que sobe e desce – de pedras a pessoas – é o operador de guincho. A máquina, movida a diesel, tem dois comandos: acelerador e freio. O guincheiro se comunica com o interior da mina por um “telefone”, que, na verdade, não passa de um tubo de PVC

Miner finds 239 carat raw diamond in Botswana

Miner finds 239 carat raw diamond in Botswana

      

239 carat raw diamond

Lucara Diamond Corp. (TSX:LUC) announced Monday it extracted a 239.2 carat diamond in Botswana.
The Karowe mine, in the central district of the southern African country, also produced two more large stones weighing 124 and 71.1 carats.
Lucara's CEO said in a written statement the 239 carat raw stone is one of the largest diamonds ever to have been recovered from the Orapa kimberlite field in more than 40 years.
He also noted the mine has confirmed it contains fancy-coloured blue diamonds, some of the most valuable and sought-after gems.
The three raw stones will be sent to Belgium to be studied and then sold later in the year.
Christie's is set to hold a multi-million-dollar auction in May for one of the world's biggest diamonds, which weighed 236 carats when it was originally extricated.
Image courtesy Lucara Diamonds

Newmont gets fresh shot at top gold miner spot

Newmont gets fresh shot at top gold miner spot

      

The Super Pit some 600km east of Perth has produced 50 million ounces over 30 years and fully developed the cut will be 3.6 kilometers long, 1.6 kilometers wide and up to 650 meters deep. Image: Kalgoorlie Consolidated Gold Mines

Barrick Gold’s (TSX, NYSE:ABX) planned sale of a 50% stake in Australia’s Kalgoorlie mine has been pushed out further after Minjar Gold, the Chinese bidder, walked away from the deal citing new capital controls instituted by Beijing.
Perth-based Minjar Gold, a unit of Shanghai-listed Shandong Tyan has also been struggling to secure funding for the deal worth as much as $1.5 billion. Its biggest offshore acquisition was Evolution Mining's (ASX:CAH) Pajingo mine for $40 million back in 2015.
Barrick president Kelvin Dushnisky told Reuters in February the Toronto-based company, the world's top gold miner by output, would be "happy sellers" at the right price, but would also be "very happy to continue to own that asset".
World number two Newmont Mining owns the other half and Barrick handed over operational control of the the iconic mine called the Super Pit to Newmont in May 2015.
Denver-based Newmont would be the natural buyer and has expressed interest in the mine, Australia's largest gold open pit, in the past. Kalgoorlie produced just over 750,000 ounces last year.
Newmont has first right of refusal on the stake sale, but Barrick could circumvent that by selling shares in Kalgoorlie's holding company KCGM.
Valuation of Kalgoorlie is all over the place with analyst estimates varying between $400 million to about $1.5 billion. Reserves at the mine top 7.5 million ounces.
The Super Pit is expected to be depleted of ore by the end of the decade but underground mining could continue after that. KCGM also operates the 56,000oz per year Mt Charlotte mine 3km from the Super Pit.
Should a transaction between the companies take place it would push Newmont past Barrick as the world's largest gold company in terms of output.

India’s Supreme Court won’t try forcing UK to return Kohinoor diamond

India’s Supreme Court won’t try forcing UK to return Kohinoor diamond

      

The 105-carat Kohinoor has been part of the British crown jewels for more than 150 years and today forms part of a crown that was worn by the late mother of Queen Elizabeth. (Images via WikiMedia Commons)

India’s Supreme Court has told officials pushing for fresh attempts to bring the priceless Koh-i-Noor diamond, now part of the British crown jewels, that it cannot interfere in the diplomatic process nor can it direct another country to not auction the gem.
The 105-carat Koh-i-Noor diamond, which came into British hands in the mid-19th Century, has been on display at the Tower of London for years. But ownership of the famous rock is an emotional issue for many Indians, who believe the British stole it.
The 105-carat diamond — one of the world’s largest — has been at the centre of a diplomatic row between New Delhi and London, with India arguing for decades that it should get it back.For that reason, the diamond — one of the world’s largest — has been at the centre of a diplomatic row between New Delhi and London, with India arguing for decades that it should get it back.
Last year, Prime Minister Narendra Modi’s administration told the Supreme Court that the diamond was neither "forcibly taken nor stolen" by the British, but given as a "gift" to the East India Company by the rulers of Punjab.
The government, however, has revealed that it is still trying to bring the diamond back, likely based on agreements with the UK, as there is no concrete evidence to show Koh-i-Noor was validly gifted to Queen Victoria, India Today reported.
The Koh-i-Noor, meaning "Mountain of Light" in Persian, has been part of the British crown jewels for more than 150 years and it is now part of a crown worn by the late mother of Queen Elizabeth.
For many Indians, the British returning the diamond would be a compensation for the excesses they committed during their colonial rule.

Vale’s iron ore output just hit another record

Vale’s iron ore output just hit another record

      

Gongo Soco mine in Brazil’s Minas Gerais state. (Image: Vale SA.)

Brazil’s Vale (NYSE:VALE), the world’s No.1 iron ore miner, said output of the steelmaking material hit a fresh record high in the first quarter as its massive S11D mine in the Amazon continued to ramp up.
Vale's iron ore output hit a fresh record high in Q1 as its massive S11D mine in the Amazon continued to ramp up.The Rio de Janeiro-based company said iron ore production jumped 11% to 86.2 million tonnes in the January-March period, compared to the same quarter a year earlier.
The figure however, was 6.7% lower than total iron ore output of 92.386 million tonnes in the prior three months, and the company said it might restrain supply even further in coming months to support prices if necessary.
For now, however, the mining giant reiterated its output guidance for the year of between 360 million and 380 million tonnes of seaborne.
The commodity has been steadily falling in the last few days, to a near six-month low this week, on the back of fresh signs of a supply glut and ramped-up production in China.
While prices have recovered slightly in the past two days — ore with 62% content in Qingdao added 76 cents overnight to $65.36 a tonne on Thursday according to the Metal Bulletin — analysts expect supply to surpass demand for the foreseeable future.

For some, such as Stan Wholley, president for the Americas at CSA Global, the current downtrend is nothing but a expected correction. “I think people got exuberant about iron ore on the way up and we are seeing a bit of reality check right now,” he told MINING.com.

He noted that at least one of the main factors dragging prices down at the moment — high level of stockpiles in China and the anticipated increases in supply coming from Vale and Roy Hill — may soon reverse its course.
“There is not a great deal that can be done about the new supply — it will happen. However, there are indications that stockpiles in China are decreasing (albeit from record highs) which may slow or even halt the decline,” he said.
“I also think the handover of power that will be occurring in China later in the year will have a stabilizing influence, as the incoming government will not want to see wild swings in the economy and will want to see growth maintained as they assume power,” said the CSA Global consultant, who has more than 25 years of experience in exploration and mining geology, particularly in the iron ore sector.
Longer term, Wholley thinks iron ore fundamentals are sound. Steel production in China increased in 2016 and it’s predicted to do so again this year to support infrastructure projects as Beijing tries to stimulate the economy.
At Macquarie, analysts seem to be on board of a very different boat. In a note Thursday, the bank said it expected to see iron ore find support at around $50 per tonne, suggesting that falls of a further 20% are in store.