igneous
Basalt
Extrusive igneous rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, typically dark gray to black in color, with an aphanitic or fine-grained texture and dull to submetallic luster.
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Physical properties
Hardness of 6 on the Mohs scale, typically dark gray to black in color, with an aphanitic or fine-grained texture and dull to submetallic luster.
Formation & geological history
Formed from the rapid cooling of low-viscosity, magnesium- and iron-rich lava exposed at or very near the Earth's surface.
Uses & applications
Widely used in construction as crushed aggregate for roads, railroad ballast, and in the production of stone wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's crust underlying the world's ocean basins and forms famous columns like the Giant's Causeway.
Field identification & locations
Easily identified by its dark, fine-grained appearance and heavy weight, commonly found in volcanic regions and oceanic crusts worldwide.
