igneous
Basalt
Extrusive igneous rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, dark gray to black color, fine-grained aphanitic texture, dull luster, and high specific gravity around 2.8 to 3.0.
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Physical properties
Hardness of 6 on the Mohs scale, dark gray to black color, fine-grained aphanitic texture, dull luster, and high specific gravity around 2.8 to 3.0.
Formation & geological history
Formed from the rapid cooling of low-viscosity basaltic lava exposed at or very near the Earth's surface, often in volcanic contexts.
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 crust underlying the world's ocean basins and also forms major volcanic features on the Moon and Mars.
Field identification & locations
Easily identified by its dark, dense, fine-grained matrix and often vesicular texture; commonly found in volcanic provinces worldwide.
