igneous
Obsidian
Volcanic Glass
AI-generated identification · may be incorrectHardness of 5 to 5.5 on the Mohs scale, deep dark green to black color, vitreous luster, amorphous crystal structure with no true cleavage, showing distinct conchoidal fracture.
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Physical properties
Hardness of 5 to 5.5 on the Mohs scale, deep dark green to black color, vitreous luster, amorphous crystal structure with no true cleavage, showing distinct conchoidal fracture.
Formation & geological history
Formed from rapidly cooling felsic lava extruded from a volcano, preventing crystal growth.
Uses & applications
Historically used for sharp cutting tools and arrowheads; currently used in jewelry, ornamental objects, and experimental surgical scalpel blades.
Geological facts
Despite being primarily silica, it lacks a crystalline lattice, which classifies it as a mineraloid rather than a true mineral.
Field identification & locations
Easily identified by its glassy texture and sharp conchoidal fracture edges; found globally near areas of recent volcanic activity.
