igneous
Obsidian
Volcanic Glass
AI-generated identification · may be incorrectHardness 5-5.5 on the Mohs scale, typically black to dark brown, vitreous luster, amorphous crystal structure with conchoidal fracture.
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Physical properties
Hardness 5-5.5 on the Mohs scale, typically black to dark brown, vitreous luster, amorphous crystal structure with conchoidal fracture.
Formation & geological history
Formed as felsic lava cools rapidly with minimal crystal growth, commonly associated with volcanic extrusive environments.
Uses & applications
Used historically for sharp cutting tools and arrowheads, currently utilized in jewelry, ornamental objects, and experimental surgical scalpels.
Geological facts
Despite its dark color, obsidian has a high silica content, usually over 70 percent. It shatters into extremely sharp edges thinner than modern steel blades.
Field identification & locations
Identified easily by its glossy vitreous luster and distinct conchoidal fracture patterns; found globally near regions of recent volcanic activity.
