igneous
Basalt
Mafic extrusive igneous rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, dark gray to black color, dull to sub-with a fine-grained aphanitic crystal structure.
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Physical properties
Hardness of 6 on the Mohs scale, dark gray to black color, dull to sub-with a fine-grained aphanitic crystal structure.
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, railroad ballast, and in the manufacturing 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 geological formations like the Columbia River Flood Basalts.
Field identification & locations
Identified by its dark color, fine-grained texture, and heavy weight; commonly found globally in volcanic provinces and oceanic crust.
