Hi York Girl,
I am sure that you and Brian are correct with RUBY.
However there was a film in 2006 called BLOOD DIAMOND starring Leonardo Di Caprio.
In relation to diamond trading, blood diamond (also called a converted diamond, conflict diamond, hot diamond, or a war diamond) refers to a diamond mined in a war zone and sold to finance an insurgency, invading army's war efforts, or a warlord's activity, usually in Africa.
However, without the number of letters, RUBY is the best bet.