igneous
Basalt
Extrusive Igneous Rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, dark gray to black color, aphanitic texture, dull luster, composed mainly of plagioclase and pyroxene.
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Physical properties
Hardness of 6 on the Mohs scale, dark gray to black color, aphanitic texture, dull luster, composed mainly of plagioclase and pyroxene.
Formation & geological history
Formed from the rapid cooling of low-viscosity lava rich in magnesium and iron exposed at or very near the Earth's surface.
Uses & applications
Used extensively in construction as crushed stone for road bases, railroad ballast, concrete aggregate, and in producing rock wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's crustal portions underlying the world's ocean basins and makes up much of the lunar maria.
Field identification & locations
Identify by its dark, fine-grained appearance and heavy weight; commonly found in volcanic regions, oceanic ridges, and flood basalt provinces.
