igneous
Basalt
Extrusive Igneous Rock
AI-generated identification · may be incorrectMohs hardness of 6, dark gray to black color, dull luster, aphanitic crystal structure, specific gravity around 2.9.
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Physical properties
Mohs hardness of 6, dark gray to black color, dull luster, aphanitic crystal structure, specific gravity around 2.9.
Formation & geological history
Formed from the rapid cooling of low-viscosity basaltic lava exposed at or near the Earth's surface.
Uses & applications
Used in construction as crushed stone for road bases, concrete aggregate, and in the production of stone wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's crustal portions underlying the ocean basins and forms massive geological formations like the Columbia River Flood Basalts.
Field identification & locations
Identify by its dark color, fine-grained texture, and high density. Found worldwide in volcanic regions and oceanic crusts.
