I would lose the light table and the under lighting. You can keep it, but I find jewelry looks better without it. Also, you are using diffuse light. To really catch the sparkle, you need to use direct lighting – consider getting some cheap honeycomb (10 or 20 degrees or so) for the direct lighting. Also, lose the cube. I’ve had one of those for years and I love it, but I don’t care for it with jewelry – it’s good for a certain look to jewelry, but you are having trouble with the setup and weird shadows – the shadows are most likely because the rest of your light is stronger than your under lighting – try one light at a time and see where the shadows and highlights go for each then combinations. If you can’t kill the shadows, try repositioning lights, lose one, then another, etc. Finally, try a more contrasted background – use a dark background (black, dark grey, blue, red, green). I have dozens of fabric bits I use for photos.
Can you send a couple test photos along? Try one with jewelry and one with something colorful like a Rubik’s cube or something similar.
Jonathan Ziegler
https://www.electrictiger.com/
520-360-8293