OBSIDIAN

Obsidian is an igneous rock that forms when molten rock cools very rapidly. The result is a rock that cooled so fast, crystals did not get a chance to form.  Obsidian is a naturally occurring volcanic glass with a smooth and uniform structure.  Obsidian is extremely rich in silica (about 65 to 80 percent), is low in water, and has a chemical composition similar to rhyolite.  Obsidian has a glassy lustre and is slightly harder than window glass.

It can be gray to black and often displays splotchy white patches or “snowflakes”. Obsidian can also be brown to orange or red and have bands or a sheen. Iridescent obsidian is known as rainbow obsidian. Small translucent rounded pieces are called Apache tears. Obsidian gets its name from a Obsius who is said to have discovered it in Ethiopia. Obsidian has been known and used since antiquity.