Canada's first surface and underground diamond mine experienced a poor year for production in 2012, according to figures posted by mining giant BHP Billiton and reported on at Diamond Intelligence. BHP says that in the 2012 calendar year, it unearthed 39% fewer carats of rough diamonds at the Ekati diamond mine in Canada's Northwest Territories than it had in 2011.

BHP added that only 295,000 carats of rough diamonds were harvested from Ekati in the fourth quarter of 2012, a significant year-over-year drop from 2011, when the mine produced 481,000 carats. Back in July, the firm said that it had only produced 1.784 million carats of diamonds in the first half of 2012, a 29% year-over-year decrease in comparison to 2011's H1.

Ekati's reduced numbers did not deter diamond company Harry Winston from making an offer to purchase the mine for $500 million. The transaction is currently on hold, pending regulatory approval and an appeal from one of the minority owners of the mine.