igneous
Basalt
Extrusive igneous rock
AI-generated identification · may be incorrectHardness of 6 on Mohs scale, dark gray to black color, aphanitic texture with fine-grained minerals, dull to sub-vitreous luster.
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Physical properties
Hardness of 6 on Mohs scale, dark gray to black color, aphanitic texture with fine-grained minerals, dull to sub-vitreous 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
Commonly used in construction as crushed aggregate, road base, 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 famous formations like the Giant's Causeway.
Field identification & locations
Identify by its dark, fine-grained appearance and heavy weight. Found globally in volcanic provinces, oceanic crust, and basalt flood traps.
