igneous
Basalt
Extrusive igneous rock
AI-generated identification · may be incorrectHardness of 6 on Mohs scale, dark gray to black color, aphanitic texture, and specific gravity of 2.8 to 3.0.
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Physical properties
Hardness of 6 on Mohs scale, dark gray to black color, aphanitic texture, and specific gravity of 2.8 to 3.0.
Formation & geological history
Formed from the rapid cooling of low-viscosity lava rich in iron and magnesium exposed at or very near the surface.
Uses & applications
Used widely in construction as crushed aggregate, railroad ballast, and in the production of stone wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's crust, primarily making up the ocean floors and volcanic islands like Hawaii.
Field identification & locations
Identified by its fine-grained dark matrix and sometimes vesicular texture; found abundantly in volcanic regions worldwide.
