Diagem recovers a 6.2 carat diamond

Diagem Inc. reports the recovery of a 6.23 carat gem-quality diamond during bulk sampling at its Chapadão Diamond Project in Mato Grosso, Brazil. The initial 68.7 cubic metre sample yielded a total of 102 commercial-size diamonds (i.e. > than 1.7mm) weighing in total 24.5 carats for a grade of 0.36 carats per cubic metre.

The recovery of a 6.23 carat gem-quality diamond so early in the bulk sampling program is extremely encouraging, though not unexpected, said Denis Francoeur, CEO of Diagem. High-value coarse diamonds have been recovered by artisanal miners on the Chapadão. An example is the valuable 9.32 carat pink diamond purchased by Diagem. What comes as a surprise is the IBAMA intervention and its obvious inaccuracies. Diagem is seeking immediate correction through legal means.

Earlier preliminary bulk sampling conducted by Diagem in November and December of 2006 recovered a total of 849 diamonds coarser than 1.7 millimetres and weighing 155 carats including a 4.67 carat diamond and eight diamonds ranging between 1.20 and 1.34 carats. The 13 original bulk samples reported diamond grades ranging between 0.28 and 1.26 carats per cubic metre with an average of 0.66 carats per cubic metre from 243 cubic metres of material.

The lower grade reported in the latest sample is attributed to excessive dilution due to local displacements which has caused the pinching and swelling of the diamondiferous layer. The expectation is that higher grades are likely to be encountered.

The bulk sampling program is designed to further delineate and determine the diamond grade of the near-surface diamondiferous kimberlitic ash-fall layer(s) outlined by auger drilling. The ash-fall diamondiferous layer is interpreted to be a pyroclastic lappilli kimberlitic tuff(s) deposited as an air fall from the eruptive explosion of kimberlite(s). The diamondiferous ash-fall layer varies in thickness between 0.5 and 2.0 metres (0.6 m on average) and covers an extensive area that could be mined with the same economic parameters of an alluvial or gravel deposit. Auger drilling has extended the deposit(s).

The surface bulk sampling was conducted with two 10 cubic metre per hour moveable plants. The resulting heavy mineral concentrates are being processed at the Company’s Juína X-Ray Separator facility for the recovery of commercial-sized diamonds.

Source : http://www.diagem.com/

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