Round shaped black and white semi precious gemstone Tuxedo Agate designer cabochon 40 mm in diameter and 5 mm thick.
This is actually semi precious stone Brazilian Agate that has been dyed a rich black!
The natural white lines come through and make a beautiful specialty designer cabochon known as Tuxedo Agate.
Agate is a form of Chalcedony, or a microcrystalline quartz. It forms in concentric layers in a wide variety of colors and textures. It has a hardness of 7 and wears great in jewelry.