igneous
Basalt
Extrusive Igneous Rock
AI-generated identification · may be incorrectHardness of 6 on Mohs scale, dark gray to black color, aphanitic texture, dull luster, high specific gravity.
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Physical properties
Hardness of 6 on Mohs scale, dark gray to black color, aphanitic texture, dull luster, high specific gravity.
Formation & geological history
Formed from the rapid cooling of low-viscosity lava rich in magnesium and iron exposed at or very near the surface.
Uses & applications
Used widely in construction, aggregate for roads, railroad ballast, and the production of stone wool insulation.
Geological facts
Basalt is the most common rock type on Earth's crust beneath the oceans and also forms extensive volcanic features like the Moon's maria.
Field identification & locations
Identified by its dark, fine-grained matrix and heavy weight; found abundantly in volcanic regions worldwide and consistent with regional geology.
