Tip # 11
Assuming you're buying a gemstone cabochon, there are several questions to ask yourself as you inspect the piece. First, a cabochon is a dome-topped piece of rock or sandstone that has a flat back and is either slung, wire-wrapped or mounted to protect it.
Look at the top of the cab; is it shiny or soft? Is there a flat spot that isn't polished or holes, native to the stone, that don't detract from the piece? Hand polished cabs are the most highly polished and are done in a series from harsh grit sanding belts to fine grit. The final polish should be lustrous and have give the rock a glow all its own.
It the cab secure in its bezel? Take the cab between two fingers and very gently try and rock it back and forth in its findings. If the bezel has a solid back you should not be able to move it at all. If it's mounted on fabric, the beads surrounding it should be tight and layer up to smaller beads as they move over the face. The sides of the cab should not be visible. If the bezel is a "sling" of beads they should be tightly woven and the cab should not "rock" inside the sling.
If the cab is not secure you should discuss that with the maker. Perhaps they can make it more secure. If they can't you'll need to decide whether you want to risk the money being asked for the piece or pass it up for another.