igneous
Basalt
Extrusive igneous rock
AI-generated identification · may be incorrectHardness 6 on Mohs scale, dark gray to black color, aphanitic texture, dull luster, specific gravity 2.8-3.0.
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Physical properties
Hardness 6 on Mohs scale, dark gray to black color, aphanitic texture, dull luster, specific gravity 2.8-3.0.
Formation & geological history
Formed from the rapid cooling of low-viscosity, mafic lava flows at the Earth's surface.
Uses & applications
Used widely in construction as crushed stone for aggregate, railroad ballast, and road construction.
Geological facts
Basalt is the most common rock type on Earth's crust beneath the oceans and also forms extensive continental flood basalts.
Field identification & locations
Identified by its fine-grained dark appearance and dense, heavy feel. Found globally in volcanic regions.
