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 a fine-grained aphanitic texture and dull to sub-metallic luster.
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Physical properties
Hardness of 6 on the Mohs scale, typically dark gray to black in color, with a fine-grained aphanitic texture and dull to sub-metallic 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 manufacturing of rock wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's oceanic crust and also makes up extensive volcanic formations on the Moon and Mars.
Field identification & locations
Identify by its dark color, fine-grained matrix, and heavy density; commonly found in volcanic regions, oceanic islands, and continental flood basalt provinces.
