Smoky is a variety of Quartz colored by trace elements built into the crystal lattice, in this case aluminum. Irradiation of aluminum impurities within the quartz produce the grayish to brownish-black color.
Smoky Quartz facilitates connection of the root and crown chakras to bring your dreams into a physical reality, the release of old stories and belief systems that no longer serve you, and helps remove radiation from the environment.