igneous
Basalt
Extrusive Igneous Rock
AI-generated identification · may be incorrectHardness of 6 on Mohs scale, typically dark gray to black in color, with a fine-grained or aphanitic texture. It often contains vesicular cavities formed by trapped gas bubbles.
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Physical properties
Hardness of 6 on Mohs scale, typically dark gray to black in color, with a fine-grained or aphanitic texture. It often contains vesicular cavities formed by trapped gas bubbles.
Formation & geological history
Formed from the rapid cooling of low-viscosity, magnesium- and iron-rich lava exposed at or very near the Earth's surface.
Uses & applications
Widely used in construction for crushed stone in road bases, concrete aggregate, and manufacturing 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 features like the Columbia River Flood Basalts.
Field identification & locations
Easily identified in the field by its dark color, heavy weight, and fine crystalline matrix occasionally featuring gas vesicles; found globally in volcanic regions.
