Quick Facts on Smoky Quartz
| Chemical Formula |
: | SiO2 |
| Mineral |
: | Cairngorm or Cairngormstone |
| Color |
: | Various shades of black and brown. |
| Hardness |
: | 7 |
| Uses |
: | Gemstone and ornamental stone. |
| Refraction |
: | 1.544-1.553 |

A brown or a
black colored quartz, smoky quartz is used for unusual faceted cuts.
The color of the stone is unusual and can be well recognized by the
general public. The commercial market of this particular stone is
very limited, because the demand for brown gemstones is not very
high. Smoky quartz is very popular as an ornamental stone. The stone
can be carved into various shape like pyramids, spheres,obilisks,
eggs, figurines and ornate statues. Sometimes smoky gray colored
stones are considered as smoky quartz. The color of the smoky quartz
is related to the amount of exposure to radiation that the stone has
undergone.
Natural smoky quartz stones are found in granitic rocks
which have a small but continuous amount of radioactivity. Besides
this, they also come from many sources around the world. A few of
the more noteworthy areas are like Brazil, which is supposed to be
the world's largest supplier, Pikes Peak area of Colorado, USA, and
the Swiss Alps, which has produced many tons of these fine stones.