Suncor Energy: Dominion Diamond Corporation

Dominion Diamond Corporation - DDC.t is a Canadian diamond mining company with ownership interests in two major producing diamond mines in Canada’s Northwest Territories. The Company operates the Ekati Diamond Mine (88.9% controlling interest) and also owns 40% of the Diavik Diamond Mine.

The company is the world’s third largest producer of rough diamonds by value.

On March 8, 2016 the company reported News

Dominion Diamond Corporation (TSX:DDC, NYSE:DDC) (the “Company” or “Dominion”) is pleased to release an updated reserve and resource statement for the Diavik Diamond Mine. The tables below summarize the mineral reserves and mineral resources at the Diavik Diamond Mine as at December 31, 2015, expressed in millions of tonnes, carats per tonne, and millions of carats.
The mineral reserves shown here account for all depletions due to production and sampling to December 31, 2015. The mineral reserves also include forecasted mining losses and dilution. Underground mining dilution and losses have been assessed regularly since the production ramp-up began in 2010. Because more than one mining method is underway in the underground mine, dilution and losses are a function of the method used, experience and observation. The future A-21 open pit is expected to have dilution and losses similar to those achieved during Diavik’s first decade as an open pit operation.
New data from surveying along with the results of new samples taken in active mining areas were incorporated into the latest reserve and resource models in calendar 2015. There were 3 new samples taken in A-154 South, 16 new samples taken in A-418 and 4 new samples taken in A-154 North. Beyond the active mining areas of A-154 North, a further 53 samples were collected from a drilling campaign to access deeper regions. This resulted in the amount of A-154 North probable reserves more than doubling to approximately 4.7 million tonnes (11.1 million carats) through the promotion of inferred resources and the addition of new kimberlite at depth.
A-21 is in development as an open pit and is on track to commence ore production in the second half of 2018.
Totals may not add up exactly due to rounding. The values shown are on a 100% basis of the Diavik Diamond Mine.

Mineral Reserves at Diavik Diamond Mine – December 31, 2015 (100% basis)

Kimberlite Pipes		PROVEN RESERVES			PROBABLE RESERVES			PROVEN AND PROBABLE
	Type	M t	ct/t	M ct	M t	ct/t	M ct	M t	ct/t	M ct
A-154 South	UG	0.3	3.2	1.1	1.2	3.4	4.0	1.5	3.3	5.1
A-154 North	UG	4.1	2.4	9.7	4.7	2.4	11.1	8.8	2.4	20.8
A-418	UG	2.6	4.1	10.9	2.0	2.9	5.8	4.6	3.6	16.7
A-21	OP	3.7	2.7	10.0	-	-	-	3.7	2.7	10.0
Stockpile	N/A	0.1	3.5	0.3	-	-	-	0.1	3.5	0.3
Sub-Total – Underground		7.1	3.1	21.7	7.9	2.7	20.9	14.9	2.9	42.6
Sub-Total – Open Pit		3.7	2.7	10.0	-	-	-	3.7	2.7	10.0
Sub-Total – Stockpile		0.1	3.5	0.3	-	-	-	0.1	3.5	0.3
Total Reserves		10.8	3.0	32.0	7.9	2.7	20.9	18.7	2.8	52.8
Note: Totals may not add up due to rounding.

The mineral reserves estimate reflects a bottom screen size of 1 mm. Stockpiles are minor run-of-mine stockpiles that are maintained at or near the process plant and are available to maintain blending of kimberlite sources to the plant.

Mineral Resources at Diavik Diamond Mine – December 31, 2015 (100% basis)

Kimberlite Pipes		MEASURED RESOURCES			INDICATED RESOURCES			INFERRED RESOURCES
	Type	M t	ct/t	M ct	M t	ct/t	M ct	M t	ct/t	M ct
A-154 South	UG	-	-	-	-	-	-	0.3	3.0	0.8
A-154 North	UG	-	-	-	-	-	-	0.5	2.4	1.2
A-418	UG	-	-	-	-	-	-	0.3	2.4	0.7
A-21	OP	-	-	-	0.4	2.6	1.0	0.8	3.0	2.3
Total Resources		-	-	-	0.4	2.6	1.0	1.8	2.8	5.0
Note: Totals may not add up due to rounding.