igneous
Basalt
Mafic extrusive igneous rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, dark gray to black color, aphanitic texture, specific gravity around 2.9.
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Physical properties
Hardness of 6 on the Mohs scale, dark gray to black color, aphanitic texture, specific gravity around 2.9.
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
Used extensively in construction as crushed aggregate, railroad ballast, and in the production of stone wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's crust underlying the world's ocean basins and forms famous formations like the Giant's Causeway.
Field identification & locations
Identified by its dark, fine-grained appearance; commonly found in volcanic regions and oceanic crusts worldwide.
