igneous
Basalt
Extrusive Igneous Rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, dark gray to black in color, dull to sub-withering luster, and a fine-grained aphanitic crystal structure.
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Physical properties
Hardness of 6 on the Mohs scale, dark gray to black in color, dull to sub-withering luster, and a fine-grained aphanitic crystal structure.
Formation & geological history
Formed from the rapid cooling of low-viscosity basaltic lava exposed at or very near the surface of a planet or moon.
Uses & applications
Widely used in construction for crushed stone in road base, aggregate in concrete, and manufacturing of rock wool insulation.
Geological facts
Basalt is the most common rock type on Earth's crust beneath the oceans and also forms massive features on the Moon and Mars.
Field identification & locations
Identified by its dark color, heavy weight, and fine-grained matrix, commonly found in volcanic regions worldwide.
