The best camera for jewelry photography should work well with a lens that provides enough working distance from the subject. A little further back can make it easier to position the lights and make it less likely that you or the camera/photographer will end up in a reflective metal surface. When selecting a camera, it is important to think about the camera and macro lens in tandem, not just the body of the camera. Visuals Clipping  suggests you select the camera and the macro lens, not just the camera body.