igneous
Basalt
Extrusive igneous rock
AI-generated identification · may be incorrectHardness of 6 on Mohs scale, dark gray to black color, aphanitic to porphyritic texture, vitreous to dull luster.
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Physical properties
Hardness of 6 on Mohs scale, dark gray to black color, aphanitic to porphyritic texture, vitreous to dull luster.
Formation & geological history
Formed from the rapid cooling of low-viscosity lava rich in iron and magnesium exposed at or very near the Earth's surface.
Uses & applications
Commonly used in construction, road aggregate, railroad ballast, and 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 Giant's Causeway.
Field identification & locations
Identify by its fine-grained dark appearance, high density, and occasional vesicular texture from trapped gas bubbles. Found globally in volcanic provinces.
