igneous
Basalt
Extrusive igneous rock
AI-generated identification · may be incorrectHardness of 6 on Mohs scale, dark gray to black color, aphanitic texture with a dull luster, and high specific gravity around 2.9.
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Physical properties
Hardness of 6 on Mohs scale, dark gray to black color, aphanitic texture with a dull luster, and high specific gravity around 2.9.
Formation & geological history
Formed from the rapid cooling of low-viscosity, iron- and magnesium-rich lava flows at the Earth's surface.
Uses & applications
Used extensively in construction as crushed aggregate, railroad ballast, and dimension stone.
Geological facts
Basalt is the most common rock type in the Earth's crustal portions underlying the ocean basins and forms massive volcanic features like the Giant's Causeway.
Field identification & locations
Identified in the field by its fine-grained, dark-colored appearance and dense, heavy feel; commonly found in volcanic regions worldwide.
