igneous
Basalt
Extrusive Igneous Rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, dark gray to black color, aphanitic texture, dull luster, and high density.
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Physical properties
Hardness of 6 on the Mohs scale, dark gray to black color, aphanitic texture, dull luster, and high density.
Formation & geological history
Formed from the rapid cooling of low-viscosity, magnesium- and iron-rich lava exposed at or very near the Earth's surface.
Uses & applications
Widely used in construction as crushed aggregate, railroad ballast, stone masonry, and in the manufacturing of rock wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's crust underlying the oceans and forms famous formations like the Giant's Causeway.
Field identification & locations
Identified by its dark, fine-grained appearance and heavy weight; found abundantly in volcanic regions worldwide.
