Let me say that I hate to explain designs, but for this specific design I think that it might be necessary.
Light vs. Dark. Good vs. Evil. The fact is that we're all made of both. And it's ultimately our choice which wins over the other. I chose to make the design a heart (sorry for being cliche!... and for the paint splatters...) because it's the usual thing people refer to about being good or evil.
I used black and white obviously to represent good and evil and light and dark. The hearts's coloring is done in the shape of the yin yang symbol. Obviously to represent good vs. evil (too much symbolism!)
The reason for the rough/rock-like texture of part of the heart is a reference to LOST and the two black and white stones that are found. (See the thumbnail for an image.) Again, this represents good vs. evil. So sorry for the tiny little LOST reference!
Simulated process on silver! (grey is a combination of black and white. Ahhhh!)