igneous
Basalt
Extrusive mafic igneous rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, dark gray to black in color, fine-grained aphanitic texture with dull luster, and high density.
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Physical properties
Hardness of 6 on the Mohs scale, dark gray to black in color, fine-grained aphanitic texture with dull luster, and high density.
Formation & geological history
Formed from the rapid cooling of low-viscosity basaltic lava exposed at or very near the Earth's surface.
Uses & applications
Widely used in construction as crushed aggregate for roads, 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 oceans and forms famous geological formations like the Giant's Causeway.
Field identification & locations
Identify in the field by its dark, heavy, fine-grained appearance; commonly found in volcanic regions and oceanic crusts worldwide.
