igneous
Basalt
Extrusive Igneous Rock
AI-generated identification · may be incorrectHardness of 6 on Mohs scale, dark gray to black color, aphanitic to porphyritic texture, sub-conchoidal fracture, and specific gravity around 2.9.
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Physical properties
Hardness of 6 on Mohs scale, dark gray to black color, aphanitic to porphyritic texture, sub-conchoidal fracture, and specific gravity around 2.9.
Formation & geological history
Formed from the rapid cooling of low-viscosity basaltic lava exposed at or very near the Earth's surface.
Uses & applications
Widely used in construction for crushed stone, road aggregate, railroad ballast, and in the production of stone wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's oceanic crust and also makes up extensive volcanic plains on the Moon and Mars.
Field identification & locations
Identify by its fine-grained dark appearance, heavy weight, and common occurrence in volcanic regions worldwide.
