igneous
Basalt
Extrusive igneous rock
AI-generated identification · may be incorrectHardness 6 on Mohs scale, dark gray to black color, dull luster, fine-grained aphanitic crystal structure, specific gravity 2.8-3.0.
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Physical properties
Hardness 6 on Mohs scale, dark gray to black color, dull luster, fine-grained aphanitic crystal structure, specific gravity 2.8-3.0.
Formation & geological history
Formed from the rapid cooling of low-viscosity basaltic lava exposed at or very near the surface of a planet or moon.
Uses & applications
Widely used in construction, aggregate for road bases, concrete production, and manufacturing of stone wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's crust, underlying most ocean basins and forming massive volcanic features like the Columbia River Plateau.
Field identification & locations
Identify by its dark, fine-grained matrix, sometimes containing vesicles or phenocrysts of olivine and plagioclase; found globally in volcanic regions.
