What is "smoky quartz"

Smoky \Smok"y\, a. [Compar. Smokier; superl. Smokiest.]

1. Emitting smoke, esp. in large quantities or in an offensive manner; fumid; as, smoky fires.

2. Having the appearance or nature of smoke; as, a smoky fog. ``Unlustrous as the smoky light.''
   --Shak.

3. Filled with smoke, or with a vapor resembling smoke; thick; as, a smoky atmosphere.

4. Subject to be filled with smoke from chimneys or fireplace; as, a smoky house.

5. Tarnished with smoke; noisome with smoke; as, smoky rafters; smoky cells.

6. Suspicious; open to suspicion. [Obs.]
   --Foote.

   Smoky quartz (Min.), a variety of quartz crystal of a pale to dark smoky-brown color. See Quartz.

alt. A brown to black variety of quartz. n. A brown to black variety of quartz.

n. a smoky yellow or brown quartz [syn: cairngorm]

Smoky quartz is a grey, translucent variety of quartz. It ranges in clarity from almost complete transparency to a brownish-gray crystal that is almost opaque. Some can also be black. Like other quartz gems, it is a silicon dioxide crystal. The smoky colour results from free silicon, formed from the silicon dioxide by natural irradiation.