igneous
Basalt
Mafic extrusive igneous rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, dark gray to black in color, aphanitic texture with a dull luster, and specific gravity around 2.8-3.0.
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Physical properties
Hardness of 6 on the Mohs scale, dark gray to black in color, aphanitic texture with a dull luster, and specific gravity around 2.8-3.0.
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 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 oceanic crust and also forms extensive continental flood basalt provinces.
Field identification & locations
Identified by its dark, fine-grained matrix and heavy weight; commonly found in volcanic regions and oceanic islands worldwide.
