Polished Celestial Eye Sphere from Madagascar - 7.6 cm - 551 g / AX439

Obsidian is a volcanic rock primarily composed of silica. Its main characteristics are its hardness and sharpness (due to its natural conchoidal fracture), which led to its use in prehistory as a tool or weapon (knife blades or arrowheads). Obsidian is generally a deep, glossy black. White spherulites formed from acicular crystals produce snowflake obsidian. Obsidians exhibiting iridescent, rainbow-like reflections are called Celestial Eye obsidian .