Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. That means, it is the rock formed as a result of cooled magma, which is the parent material. It is an acidic rock , dark with glassy texture (is regarded as natural glass) and has been used due to its formation and durability, since the end of the Upper Paleolithic period to manufacture blades with sharp edges, used for knives and razors. It is a 5-5.5 of hardness at the Mohs scale. Obsidian can be found in locations which have experienced rhyolitic eruptions, such as Argentina, Armenia, Azerbaijan,Canada, Chile, Greece, El Salvador, Guatemala, Iceland, Italy, Japan, Kenya, Mexico, New Zealand, Peru, Scotland and the United States.
Obsidian, according to tradition, is a very powerful and creative stone. It increases self-control. It aids the digestion and detoxifies. It reduces arthritis pain, joint problems and cramps.
Zodiac: Scorpio, Sagittarius.