Ah, great idea. Hard to tell that those are diamonds though. I do not shoot jewelery but notice that diamonds are frequently photographed on white backgrounds. A tighter crop would show them off better too.
I like this concept. The stark contrast is excellent. The diamonds lack their scintillation or color flashes though. I my experience you need different lighting for the diamonds as opposed to the rest of the shot.
Clever. I think I would prefer it if the two rocks in front of the diamonds weren't there - they are a little distracting from the subject. I like the black.