igneous
Basalt
Extrusive igneous rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, dark gray to black color, aphanitic to porphyritic texture, and dull luster.
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Physical properties
Hardness of 6 on the Mohs scale, dark gray to black color, aphanitic to porphyritic texture, and dull luster.
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 for crushed stone, aggregate, railroad ballast, and in the production of rock wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's crustal portions underlying the ocean basins and also forms major continental flood basalt provinces.
Field identification & locations
Identified by its fine-grained dark matrix and sometimes visible olivine or pyroxene phenocrysts; found globally in volcanic regions.
