Get the NIKKOR Z MC 105mm f/2.8 VR S. The best lens for product/Jewelry photography.

If you're on the newer Z system, definitely consider the Nikon NIKKOR Z MC 50mm f/2.8 Macro Lens - you can get great closeup shots of the jewelry items because of the 50mm focal length and small minimum focusing distance of just 0.16m / 6.3 inches. The lens also has a 1:1 magnification ratio to give you lifelike detail in your images.

The 50mm focal length is also similar to our vision and thus will allow you to create realistic jewelry photos on models from various angles and crops. You can still get superb background separation too and create bokeh effects due to the f/2.8 maximum aperture.

Any Macro lens for Z-mount is recommended, I also love the Z MC 105mm f/2.8 VR S.

TL;DR: 1:1 magnification often isnt enough for tiny jewelry details. Go for a lens with 2x magnification like the Laowa 90mm to really see the facets. In my experience, everyone jumps to the 105mm because its the gold standard, but I have found it a bit limiting for the really small stuff like 2mm stones or hallmark stamps. Years ago I was struggling with cropping in way too much on my files and losing all that crispness. Once I tried a lens with 2:1 magnification, it was a total game changer for my workflow. I would actually disagree with the native glass suggestions and look at the Laowa 90mm f/2.8 2x Ultra Macro APO. It is manual focus, but since you are using that Foldio360 Smart Dome on a tripod, that does not matter at all. The APO design is the real winner here. It basically eliminates the purple and green color fringing you usually get on shiny gold or silver edges. It usually runs around 500 dollars. Quick tip tho... since youre on a Z6III, use the focus shift shooting mode. Even at f/11, the depth of field is tiny, so youre gonna need to stack images to get the whole ring sharp from front to back.

Some old F-mount Macro lens is also recommended.

Waiting for Sigma to release Z-mount macro lenses.

For full-frame bodies, that 105mm macro is hard to beat, but if you're on DX consider how the crop factor affects your working distance. The 60mm becomes roughly equivalent to a 90mm on DX, which is actually a sweet spot for jewelry work. I shoot with a D7500 and the 60mm micro gives me perfect magnification and working distance for most pieces. The money you save versus the 105mm can go toward better lighting, which is honestly more important than having the absolute best lens.