Smoky Quartz 25x18 Rectangle Cabochon

Smoky Quartz is a translucent smoky brown or gray variety of Quartz. It ranges from almost completely transparent to an almost opaque brownish-gray crystal. The color of Smoky Quartz is due to natural irradiation and traces of aluminum within the crystal lattice of the stone. Smoky Quartz it the national gem of Scotland, where it was mined since around 300 BCE.