igneous
Basalt
Extrusive Igneous Rock
AI-generated identification · may be incorrectHardness 6 on Mohs scale; dark gray to black color; fine-grained aphanitic texture; dull luster.
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Physical properties
Hardness 6 on Mohs scale; dark gray to black color; fine-grained aphanitic texture; dull luster.
Formation & geological history
Formed from the rapid cooling of low-viscosity lava rich in iron and magnesium exposed at the Earth's surface.
Uses & applications
Used extensively in construction as crushed stone for road bases, concrete aggregate, and dimension stone.
Geological facts
Basalt is the most common rock type on Earth's crust, underlying most ocean basins and forming planetary crusts throughout the solar system.
Field identification & locations
Identify in the field by its dark, dense, fine-grained appearance and frequent vesicular texture; common globally in volcanic provinces.
