is this like a token for a computer game? like a piece of a board puzzle game?
what I thing you could add would be a bit of bevel in the edges, and then, as the shine whent through, you could have it wrap around the surface. that would also give you the ability of using that to show cracks of bumps on the surface. if you wanna do cracks and bump on the other side also, or simulate refraction for that matter, you could use brighter colors, so it gives it a bit of depth.
right now it looks like a flat peice of reflective metal. there isnt a sugestion of transparency and depth.
take care
Kaz