igneous
Basalt
Mafic extrusive igneous rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, dark green to black color, fine-grained aphanitic texture, dull luster, specific gravity around 2.9 to 3.0.
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Physical properties
Hardness of 6 on the Mohs scale, dark green to black color, fine-grained aphanitic texture, dull luster, specific gravity around 2.9 to 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
Used extensively in construction as crushed stone for road bases, railroad ballast, and aggregate in concrete.
Geological facts
Basalt is the most common rock type in the Earth's crust underlying the world's ocean basins and forms massive volcanic formations like the Columbia River Basalt Group.
Field identification & locations
Easily identified by its dark, dense, fine-grained appearance, and commonly found in volcanic regions worldwide including the Main Ethiopian Rift.
