The way I would do this is put the subject on a light table (evenly backlit surface with a diffuse translucent material) and light the subject from the sides.

As a quickie experiment, I shot a pocket watch with fob using a light table (used for doing graphics layout in the days of yore) with a couple work lights (5000°K) shinning on the walls in a small closet with white walls. I normally wouldn't use a closet as a shooting environment, but my light modifiers are at work. I angled the lights in a smidgen to get some direct light to add highlights. You can see the cardboard box used to hold the lights in the reflections on the right. Using continuous lights makes dealing with these horrid little reflections a bit easier to fix.

Set your camera exposure so the background light is just going in to clipping. Use your camera's highlight (zebra stripe) view mode to show when the background starts clipping.
Set up your main lights to properly expose the subject and provide the desired highlights.
It's best if your back light and main lights are the same color temperature. If not, you need to over expose the background light more to make the background white. Too much overexposure can cause blooming.

In post processing, adjust the exposure to make the background clipped, or nearly clipped (i.e. white).
Adjust other exposure controls (contrast, shadows, clarity, ...) to properly expose the subject to your liking.

After a few minutes of post process fiddling in Lightroom, the final shot.

This is the setup. The box holding the work lights was moved away from the light table to show the light table setup. There is very little cost for this setup.