Quick Facts on Obsidian Stone
| Chemical Formula |
: | SiO2 |
| Color |
: | Dark green to dark brown and black |
| Hardness |
: | 5.0- 5.5 |
| Specific Gravity |
: | 2.6 |

Obsidian is
a hard volcanic glass that displays shiny and curved surfaces. It is
formed as a result of volcanic lava coming in contact with water.
This glassy, lustrous mineral is found in lava flows, and obsidian
stones can be massive. Obsidian is formed when viscous lava (from
volcanoes) cools rapidly. The stone sometimes may contain small
bubbles of air aligned along layers that produce interesting effects
such as a golden sheen, known as Sheen Obsidian or a rainbow sheen
called Rainbow Obsidian.
Obsidian is often confused with smoky quartz because of a similar
chemistry. It has been used by ancient people as a cutting tool, for
weapons, and for ceremonial purposes. The stone is found in the
regions of Italy; Mexico; Scotland; Arizona, Colorado, Texas, Utah
and Idaho, USA.