Windhoek: Police in Namibia are hunting for a 78-carat diamond after the gem went missing during a recent strike by 1,500 workers of the Namibia Diamond Trading Company.

NDTC, like the mining firm Namdeb, is a 50-50 joint venture between Anglo American’s De Beers unit and the Namibian government with a history dating back to the 1920s.

Bloomberg reports the value of the stone will “depend on the quality and size of the polished stones that can be cut from it,” but points to a 78-carat diamond mined from the Ekati mine in Canada’s north which sold for $6 million.

The Ekati Spirit was sold by BHP Billiton in 2011 and at the time described as “the most valuable stone in the mine’s 13-year history.” BHP has since exited the diamond business.

The Namibian government is in the process of changing its arrangement with Namdeb and NDTC and could set up its own selling organization.

Namdeb, the second largest employer in Namibia, sends the bulk of its production to De Beers sorting facilities in neighbouring Botswana, the world’s number one diamond producer, where it is mixed with other De Beers stones. After that, only 10% of the total sent is returned to Namibia, where they are sold through NDTC.

Namibia has the richest known marine diamond deposits in the world, estimated at more than 80 million carats. They represent approximately 64% of Namdeb’s total diamond production of 1.8 million carats and 90% of its diamond resources.