igneous
Basalt
Mafic extrusive igneous rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale. Typically dark grey to black with a fine-grained, aphanitic texture.
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Physical properties
Hardness of 6 on the Mohs scale. Typically dark grey to black with a fine-grained, aphanitic texture.
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 for crushed stone, railroad ballast, and aggregate, as well as in stoneware and tiles.
Geological facts
Basalt is the most common rock type on the Earth's crust, making up most of the ocean floor and major volcanic islands.
Field identification & locations
Easily identified in the field by its dark color, heavy weight, and fine-grained matrix, frequently found in volcanic regions.
