igneous
Basalt
Mafic extrusive igneous rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, typically dark gray to black in color, with a fine-grained aphanitic texture and dull luster.
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Physical properties
Hardness of 6 on the Mohs scale, typically dark gray to black in color, with a fine-grained aphanitic texture 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 widely in construction as crushed aggregate for roads, railroad ballast, 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 also forms massive features like the Columbia River Flood Basalts.
Field identification & locations
Identified by its dark color, fine-grained matrix, and heavy density, commonly found in volcanic regions and oceanic crusts worldwide.
