Views of the global diamond production outlook diverged at an industry summit held in Johannesburg this week.

Speaking at the Southern African Institute of Mining and Metallurgy's 'Diamonds - Source to use 2007' conference, MSA Geoservices director and consulting geologist Frieder Reichhardt said that significant opportunities existed in West Africa, specifically Guinea, Sierra Leone and Liberia.

He said that the countries shared one of the main cratons (diamondiferous kimberlites occur in cratons) on the continent and that, in the 1960/70s, the countries accounted for some 200-million to 250-million carats collectively.

Reichhardt noted that, with the political turbulence of previous decades largely reformed a number of US juniors were starting to make their mark in the region and he was expecting to see several new mines coming on line in the next few years.

Still on the continent, Angola was also mentioned as a country with "huge potential" for further diamond mining, particularly hard-rock mining, as Reichhardt noted that there are currently only two operational.

There are seven large alluvial mining operations in the country, and he did not doubt that that there would be some mines, both hard rock and alluvial, starting up in the future, which would add to production.

Reichhardt forecast that Angola's yearly production would exceed 12-million carats by 2010, and probably close to 15-million by 2015.

De Beers' Patrick Bartlett did not share this optimistic view. While he did not dispute that there were hundreds of hectares of kimberlites yet to be mined in the country, he doubted that there would be a find of similar value to historical big finds such as Botswana's Jwaneng and Orapa mines, for example.

Bartlett reiterated that the industry needed to find new diamond resources of high value and volume that would have a tangible impact on global production.

"There have been no major finds in sub-Saharan Africa since the early 1970s, and production from major mines worldwide has reached a peak or is in decline, talking mainly about kimberlites, with Canada being the only major new find in recent times," Bartlett commented.

He added that many of the world's most notable diamond operations, such as Alrosa's Udachny and Mirny mines, Rio Tinto's Argyle and De Beers' Kimberley mines will reach their peak within the next twenty years and production will then be set to decrease.

Bartlett explained that many older mines now had to go underground if production from these sources is to continue - Debswana's Jwaneng and Orapa mines and De Beers' Venetia will be going underground.

Construction of the Jwaneng and Orapa underground mines needs to start around 2015/16, Bartlett noted, and as the mines move below surface production can be expected to decrease substantially. He projects by as much as 50% or 16-million carats, this is exacerbated by the fact that the kimberlite pipe tapers dramatically. Jwaneng, with a pipe area of 54 ha at surface, is said to have a total pipe area of 12 ha at 1 000 m below surface.

The Botswana mines are not unique in the loss of production with the move underground, in his presentation at the conference, Bartlett forecast that the major diamond producers would all lose critical percentages of their production in the move underground.

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