igneous
Basalt
Extrusive igneous rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, dark gray to black in color, fine-grained aphanitic texture with a dull luster, and composed mainly of plagioclase feldspar and pyroxene.
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Physical properties
Hardness of 6 on the Mohs scale, dark gray to black in color, fine-grained aphanitic texture with a dull luster, and composed mainly of plagioclase feldspar and pyroxene.
Formation & geological history
Formed from the rapid cooling of low-viscosity, magnesium- and iron-rich lava flows at the Earth's surface.
Uses & applications
Widely used 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 crustal foundations, notably forming most of the oceanic crust and massive volcanic features like the Columbia River Basalts.
Field identification & locations
Easily identified by its dark, dense, fine-grained matrix often showing vesicular cavities from trapped gas bubbles; commonly found globally in volcanic regions.
