Smoky Quartz
Hardness: 7 Color: brown, brownish gray, blackish Formula: SiO2 Crystal System: trigonal It got its name from its color, which is the result of natural radiation. It is the brownish, greyish variety of quartz crystals. The totally dark, black crystals are called morions. Sometimes artifically radiated quartz or rock crystals are sold as smoky quartz....