igneous
Basalt
Mafic extrusive igneous rock
AI-generated identification · may be incorrectHardness of 6 on Mohs scale, dark gray to black color, aphanitic texture with visible plagioclase phenocrysts, and dull luster.
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Physical properties
Hardness of 6 on Mohs scale, dark gray to black color, aphanitic texture with visible plagioclase phenocrysts, and dull luster.
Formation & geological history
Formed from the rapid cooling of low-viscosity, magnesium- and iron-rich lava flows at the Earth's surface.
Uses & applications
Used extensively in construction as crushed stone for road bases, concrete aggregate, and in manufacturing stone wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's crust underlying the world's ocean basins and forming massive volcanic plateaus.
Field identification & locations
Identify in the field by its dark, fine-grained groundmass often containing small white crystals, commonly found in volcanic regions.
