In depth tutorial on photographing and editing rings.

https://www.newamsterdamphotovideo.com/post/ring-jewelry-photography-tutorial-shooting-and-editing-rings

Sections :
0:35 Setting up
2:01 Lighting Setup
4:13 Focus Stacking
6:10 Focus Stacking in Photoshop
8:08 Pathing
12:33 Retouching
18:15 Color Correction
22:03 Sharpening
23:14 Cropping
24:02 Stone Compositing

source