igneous
Basalt
Mafic extrusive igneous rock
AI-generated identification · may be incorrectHardness 6 on Mohs scale; dark gray to black color; aphanitic to porphyritic texture with dull luster.
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Physical properties
Hardness 6 on Mohs scale; dark gray to black color; aphanitic to porphyritic texture with 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 as crushed stone for road bases, concrete aggregate, and dimension stone.
Geological facts
Basalt is the most common rock type in the Earth's crustal oceanic plates and also forms extensive volcanic provinces on continents.
Field identification & locations
Identified by its fine-grained dark matrix, heavy feel, and occasional vesicles; found globally in volcanic regions.
