igneous
Basalt
Mafic extrusive igneous rock
AI-generated identification · may be incorrectHardness of 6 on Mohs scale, dark gray to black color, aphanitic texture, dull luster, composed primarily of plagioclase feldspar and pyroxene.
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Physical properties
Hardness of 6 on Mohs scale, dark gray to black color, aphanitic texture, dull luster, composed primarily 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 aggregate, railroad ballast, dimension stone, and in the manufacturing of rock wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's crust, underlying most ocean basins and forming massive plateau formations like the Columbia River Basalt Group.
Field identification & locations
Identify by its dense, fine-grained dark matrix and sometimes vesicular texture; found globally in volcanic regions and oceanic crusts.
