igneous
Obsidian
Volcanic glass
AI-generated identification · may be incorrectHardness of 5 to 5.5 on the Mohs scale, typically black or dark brown in color, with a vitreous luster and conchoidal fracture.
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Physical properties
Hardness of 5 to 5.5 on the Mohs scale, typically black or dark brown in color, with a vitreous luster and conchoidal fracture.
Formation & geological history
Formed as felsic lava cools rapidly with minimal crystal growth, commonly found in areas of recent volcanic activity.
Uses & applications
Historically used for making sharp tools, arrowheads, and blades, and currently used in jewelry and decorative objects.
Geological facts
Obsidian fractures with extremely sharp edges, often making blades thinner and sharper than high-quality steel surgical scalpels.
Field identification & locations
Easily identified by its glassy appearance and sharp conchoidal fracture, found worldwide near volcanic regions.
