igneous
Basalt
Extrusive Igneous Rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, typically dark gray to black in color, with an aphanitic or glassy texture and dull luster.
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Physical properties
Hardness of 6 on the Mohs scale, typically dark gray to black in color, with an aphanitic or glassy texture and dull luster.
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 as crushed aggregate for roads, railroad ballast, and in the production of rock wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's crust underlying the world's ocean basins and forms massive features like the Columbia River Flood Basalts.
Field identification & locations
Identified by its fine-grained, dark-colored matrix and heavy weight; commonly found globally in volcanic provinces and oceanic crusts.
