Source: Zim to start extracting conglomerate diamonds | The Herald January 18, 2017
Lloyd Gumbo Senior Reporter—
Zimbabwe is expected to start extracting conglomerate diamonds in the Marange fields soon, that have more value compared to the alluvial diamonds that have been mined in the area so far.
Officials from Government-owned Zimbabwe Consolidated Diamond Company (ZCDC) said the firm had started buying efficient technology to mine the conglomerate diamonds, which are located deeper than the alluvial ones.
This would see Zimbabwe matching other diamond producing countries in the region such as Botswana, Angola, South Africa and Namibia.
Speaking during a tour of Marange diamond fields by the Parliamentary Portfolio Committee on Mines and Energy last week, ZCDC acting chief executive Dr Ridge Nyashanu said they were contracting miners and mobilising resources to buy their own machinery.
He said ZCDC was now in charge of diamond processing, as he acknowledged that their initial projections of about seven million carats per year could not be met as a result of a number of challenges.
“As ZCDC, we are moving to the conglomerate, but still we have not yet moved to the source of the diamonds, which are the kimberlites,” said Dr Nyashanu.
According to the Diamond Facts website, alluvial diamonds are mainly found on the surface — in sand, gravel and clay — as a result of natural erosive action.
These are usually the ones small-scale miners can use basic equipment like sieves, shovels and pans to dig up.
Conglomerate diamonds are a rock consisting of individual stones (larger than sand) that have been cemented together and require highly mechanised machinery to extract.
Another type of the gems is the kimberlite, an igneous rock best known for sometimes containing diamonds and occurs in the earth’s crust in vertical structures known as kimberlite pipes.
“We still have to locate those kimberlites, but with the information that we have, we almost know where the kimberlites are,” said Dr Nyashanu.
“We just need to do exploration and verify.
“We are now focusing on the secondary source of the diamonds, which are the conglomerates, which is more consistent in terms of the grades, although it’s more expensive to extract. I think we are heading towards the right direction.”
Dr Nyashanu said they expected to increase production as they gain access to some of the concessions that were subject to court challenges.
Mbada Diamonds, Anjin Investments and Jinan approached the courts after Government did not renew their mining grants early last year to continue with their work in Marange.
Dr Nyashanu said since they could not access some of the concessions, they ended up producing about 953 000 carats between March and December last year, instead of their initial projection of about seven million carats per year.
He told the MPs that indications were that production was already going down even before Government stopped diamond companies from extracting gems in Marange.
“When you look at what these companies produced prior to the stopping of operations, it shows that they were on a downward trend and it’s clearly illustrated by the creditors that they had,” he said.
“This projection was not the best of projections, but we have another projection and I think now we know because (before) we could not even access Anjin and Jinan (because of court challenges). The projections were based on assumptions because of the court actions.
“We have only been mining in two portals, but now there are more portals that are coming online, so we expect our production to increase accordingly.”
The Zimbabwe Environmental Law Association sponsored the trip of the committee chaired by Zanu-PF MP for Masvingo Urban Cde Daniel Shumba.