LAC DE GRAS, Northwest Territories The latest 19,342-t sample from the A-154 North pipe in the Diavik mine is estimated to contain 11,771 ct with a value of US$82/ct. The estimate was made by WWW International Diamond Consultants within a confidence envelope of 13% at a 95% confidence level, reported ABER DIAMOND CORP., which holds 40% of the project. The remaining 60% is held by DIAVIK DIAMOND MINES (DDMI), a subsidiary of RIO TINTO.
The diamonds were recovered from kimberlite extracted by mining the low-grade upper geological unit of the A-154 North pipe. This unit is a fine-grained, graded layer of kimberlite ash and lapilli tuff that occupies the upper 40 m of the pipe. The diamonds recovered have characteristics similar to those seen in the A-154 South production. A comparison of size and value distribution data suggests that these diamonds are generally consistent with those collected from the large diameter drill core samples extracted earlier throughout the A-154 North pipe as part of the pre-feasibility study resource estimation. The overall resource grade of the A-154 North pipe, estimated from the large diameter drilling campaign, is 2.4 ct/t with a total of 27.5 million ct being contained within the overall A-154 North resource of 11.5 million t.
The A-154 South and North kimberlite pipes are two of four orebodies currently included in the Diavik project. The operator, DDMI, is currently completing the reserve reconciliation for the first pipe, A-154 South. Once this is complete DDMI will revise the mine plan to take into account the findings from this work and the bulk sample of A-154 North.
Learn more about Canada’s second diamond mine at www.diavik.ca or read about Canada’s original diamond mine, Ekati, at www.aurias.com.