I had heard about a new way to make synthetic diamonds that were literally indistinguishable from the "real thing" (which is soaked in DeBeers blood). Today in Salon the cover story deals with the move to get synthetic diamonds on the market.
Given the assumptions about black consumption patterns--which actually aren't born out by the data but I digress--I think that black Americans could probably do a pretty good job of putting the DeBeers on their back for good. The first person who can meld black nationalist rhetoric/realities to the sale of synthetic diamonds is going to have a diamond mine at their feet.