This article is about volcanic glass. For other uses see obsidian (disambiguation).

Obsidian was highly valued in certain Stone Age cultures because, like flint, it can be fractured to produce sharp blades or arrowheads. Like all glass and some other types of naturally occurring rocks, obsidian breaks with a characteristic conchoidal fracture. It may also have been polished to create early mirrors.



Pre-Columbian Mesoamericans' use of obsidian was extensive and sophisticated, including carved and worked obsidian for tools and decorative objects (see Obsidian use in Mesoamerica). The ancient Mesoamericans also made a type of sword with obsidian blades mounted in a wooden body. Called a Maquahuitl, the weapon was capable of inflicting terrible injuries, combining the sharp cutting edge of an obsidian blade with the ragged cut of a serrated weapon. Several eyewitness reports claim to witness it cleaving off opponents' limbs, heads, and even the head of an unlucky cavalry horse.