Very nice and detailed. Rings symbolizes love and affection. The image should set that mood. It would be better if you make the diamond a bit shiny than the ring itself because the diamond would mix up with the ring. It is not clear and on the sides. on first glance, it would look like it was carved. It would be better if you put more details on it.
Accurate 3d modeling and rendering.
How did you make the diamond shader?