OBSIDIAN CHARACTERISTICS Origin of the name: discovered by an ancient Roman character “Obsius”. Chemical Composition: Vitreous rock of volcanic origin based on silica. Hardness: Between 5 and 5.5. Deposits: Armenia, United States, Japan, Iceland, Mexico, Peru. Color(s): Mahogany brown, gray, black. History and Legends: Lithotherapy Properties: Physical Properties: Signs of the zodiac: Chinese signs: Chakra: