igneous
Basalt
Mafic extrusive igneous rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, dark gray to black color, aphanitic texture with fine-grained minerals, dull luster, and high specific gravity.
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Physical properties
Hardness of 6 on the Mohs scale, dark gray to black color, aphanitic texture with fine-grained minerals, dull luster, and high specific gravity.
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 extensively in construction as crushed aggregate for roads, railroad ballast, and in the production of rock wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's oceanic crust and also forms extensive continental flood basalts.
Field identification & locations
Identified by its dense, dark, fine-grained appearance, often found in volcanic regions and oceanic islands worldwide.
