igneous
Basalt
Mafic extrusive igneous rock
AI-generated identification · may be incorrectHardness of 5-6 on the Mohs scale, dark gray to black color, fine-grained aphanitic texture, dull luster.
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Physical properties
Hardness of 5-6 on the Mohs scale, dark gray to black color, fine-grained aphanitic texture, 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 extensively in construction as crushed stone for road bases, concrete aggregate, and dimension stone.
Geological facts
Basalt is the most common rock type in the Earth's crust underlying the oceans and forms massive geological features like the Columbia River Basalts.
Field identification & locations
Identified by its dark color, fine-grained texture, and heavy weight; found globally in volcanic regions and oceanic crusts.
