Rectangle or bar shaped semi precious stone black and white Tuxedo Agate designer cabochon 38.5 mm by 17.5 mm and 3 mm thick.
This is actually semi precious gemstone 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.