Obsidian

Overview

Obsidian is a natural volcanic glass, formed when felsic lava cools so quickly that crystals have no time to grow. It is glossy, smooth, and usually jet black, with a distinctive glassy fracture that produces curved, razor-sharp edges. Strictly speaking it is not a true crystal or mineral, because it has no ordered crystal structure. Most retailers still sell it under "crystals", so use the wording that suits your customers, but avoid calling it a mineral in technical descriptions.

Origin and Name

The name is traced to Obsius, a Roman said by Pliny the Elder to have found the stone in Ethiopia. Obsidian forms wherever silica-rich volcanic activity occurs, including Mexico, the USA, Iceland, Japan, Italy, Turkey, and Armenia.

It is one of humanity's oldest materials. Stone Age peoples shaped it into knives, arrowheads, and scrapers because it can be flaked to an edge sharper than steel. The Aztecs and Maya polished it into mirrors and ritual objects, and the god Tezcatlipoca was called the "Smoking Mirror". In 16th-century Europe, the scholar John Dee reportedly used an obsidian mirror for scrying.