Not sure how to rate this as personally find still lifes a bit boring,having said that I think your composition is good, but it might have been better to get the jeweled bits of the rings directed up a bit to catch a bit more light to add interest and ensure the sharpness (depth of field)is over the whole of the objects unless you wanted the blurred effect. Might be worth experimenting with taking the picture from different angles too.
I love still life, but something is missing. I just can't put my finger on it. But I like how you positioned the rings and I like the back drop you chose. Maybe if the diamonds on the ring to the left was a little more brilliant. That is probably it. Other than that Nice Shot.
[font=Arial][size=4]Diving into this industry head first!