blood diamond

noun

: a diamond sold to fund violent insurrection in the region from which it is mined

The minister [Peter Hain] also called for a boycott of diamonds from rebel sources in Sierra Leone and other countries where they were being used to finance civil wars in other parts of Africa. He said: "Someone going into a jewellery shop should insist that what they are buying is not a blood diamond but a clean diamond."—

Kim Sengupta, The Independent (London), 23 May 2000

The feds have long suspected it has profited from blood diamonds out of Africa …—

Nathan Vardi, Forbes, 14 Aug. 2006

We argued bitterly, Przemek denouncing engagement as a vulgarly commercialized American custom—I think he even made reference to the blood diamonds of Burundi …—

Vogue, February 2006

called also conflict diamond