igneous
Basalt
Extrusive Igneous Rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, typically dark gray to black in color, with a dull luster and a fine-grained aphanitic texture.
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Physical properties
Hardness of 6 on the Mohs scale, typically dark gray to black in color, with a dull luster and a fine-grained aphanitic texture.
Formation & geological history
Formed from the rapid cooling of low-viscosity lava rich in magnesium and iron exposed at or very near the surface of a planet or moon.
Uses & applications
Used extensively in construction as crushed stone for road bases, concrete aggregate, and in the manufacturing of rock wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's crust underlying the world's ocean basins and forms dramatic columnar jointing formations like the Giant's Causeway.
Field identification & locations
Identify by its dark, dense appearance, fine-grained matrix, and common presence in volcanic regions worldwide.
