igneous
Basalt
Mafic extrusive igneous rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, dark gray to black color, dull luster, microcrystalline structure, specific gravity around 2.9.
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Physical properties
Hardness of 6 on the Mohs scale, dark gray to black color, dull luster, microcrystalline structure, specific gravity around 2.9.
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 in the production of stone wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's crustal portions underlying the ocean basins and forms famous formations like the Giant's Causeway.
Field identification & locations
Identified in the field by its dense, dark, fine-grained matrix and is globally abundant in volcanic regions and oceanic crust.
