Crystals of Smoky Quartz
Beware of imitation smoky quartz crystals when buying natural stones! Two types of imposter stones you may find are man-made glass crystals and artificially darkened quartz or artificially enhanced smokey quartz.
Glass imitation crystals are exceptionally large and usually originate in China. Quartz which has been artificially enhanced will be very dark - almost black - and not "smokey" and transparent like natural quartz. The crystal may have a white base. Genuine smoky quartz crystals are transparent and you will see slight variations in color throughout the stone.