Tests Will Tell if Big Stone Is Indeed Gem

A South African mining company will know soon if they’ve found the world’s largest diamond, with tests scheduled for next week. The light-green stone was found several days ago; experts say it may turn out to only a fluorite crystal, the BBC reports. A spokesman for De Beers, the world' s biggest diamond miner, said a positive result on the gem would make it the stone of the century.

The unnamed and potentially very lucky company is standing by its rock. But critics wonder whether a diamond so massive could even exist—and say the area in a northwest province that yielded the ballyhooed object doesn’t have a rep for yielding jewels. (More De Beers stories.)