igneous
Basalt
Extrusive Igneous Rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale. Dark gray to black in color with a fine-grained, aphanitic texture and dull luster.
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Physical properties
Hardness of 6 on the Mohs scale. Dark gray to black in color with a fine-grained, aphanitic texture and dull luster.
Formation & geological history
Formed from the rapid cooling of low-viscosity lava rich in iron and magnesium exposed at or near the Earth's surface.
Uses & applications
Widely used in construction as crushed stone for road bases, concrete aggregate, and in manufacturing stone wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's crust underlying the ocean basins and forms massive column formations like the Giant's Causeway.
Field identification & locations
Identify by its dark, heavy, fine-grained appearance; commonly found globally in volcanic regions and ancient lava flows.
