If you can accept something which is a plausible ring, but not an exact copy and you can use Illustrator, then you can get the result in a minute:
The shape in the left (=a circle + a rectangle, united in the pathfinder panel) has got 3D effect Revolve. See the effect dialog. The shading can be adjusted by playing with the lights. I inserted 2 extra lights to get enough highlights.
The small parts at 12 a'clock can also be created as revolutions. There's another ring and a sphere.
The parts can be copied and pasted to Photoshop in high res for fine tuning. Often contrast must be added because Illustrator easily makes too dark shading.