De Beers' explored for diamonds in the Southern African nation between 2005 and 2012, but relinquished its concession after finding no economically viable project.
While diamonds are the most strictly checked raw materials in the world, there is a certain amount of illegally traded gems that make it into the market.
A PwC survey shows that only 4% of the 700 companies polled across 15 industries said they have completed a draft of their SEC conflict minerals filings.