igneous
Basalt
Mafic extrusive igneous rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, typically dark gray to black in color, with a-phanitic or fine-grained texture and dull to sub-vitreous luster.
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Physical properties
Hardness of 6 on the Mohs scale, typically dark gray to black in color, with a-phanitic or fine-grained texture and dull to sub-vitreous luster.
Formation & geological history
Formed from the rapid cooling of magnesium- and iron-rich lava exposed at or very near the Earth's surface.
Uses & applications
Widely used in construction as crushed stone for road bases, railroad ballast, and in the production of concrete.
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, fine-grained appearance, heavy weight, and common occurrence in volcanic terrains worldwide.
