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 fine-grained aphanitic crystal structure and dull luster.
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Physical properties
Hardness of 6 on the Mohs scale, typically dark gray to black in color, with a fine-grained aphanitic crystal structure and dull luster.
Formation & geological history
Formed from the rapid cooling of low-viscosity, magnesium- and iron-rich lava flows at or near the Earth's surface.
Uses & applications
Widely used in construction as crushed aggregate, road base, 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 columns like the Giant's Causeway.
Field identification & locations
Identified by its dark, heavy, fine-grained appearance; commonly found in volcanic regions and oceanic crusts worldwide.
