igneous
Basalt
Extrusive Igneous Rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, dark gray to black color, dull luster, aphanitic crystal structure, specific gravity around 2.9.
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Physical properties
Hardness of 6 on the Mohs scale, dark gray to black color, dull luster, aphanitic crystal structure, specific gravity around 2.9.
Formation & geological history
Formed from the rapid cooling of low-viscosity basaltic lava exposed at or very near the Earth's surface.
Uses & applications
Used extensively in construction, aggregate for roads, production of rock wool insulation, and occasionally as dimension stone.
Geological facts
Basalt is the most common rock type in the Earth's crust underlying the world's oceans and also forms major volcanic features on the Moon and Mars.
Field identification & locations
Identify by its fine-grained, dark-colored matrix often containing small visible crystals of olivine or plagioclase; globally abundant in volcanic regions.
