igneous
Basalt
Extrusive igneous rock primarily composed of plagioclase and pyroxene
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, typically dark gray to black in color, with an aphanitic or fine-grained texture and dull luster.
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Physical properties
Hardness of 6 on the Mohs scale, typically dark gray to black in color, with an aphanitic or fine-grained texture and dull luster.
Formation & geological history
Formed from the rapid cooling of low-viscosity lava rich in magnesium and iron exposed at or very near the surface of a planet or moon.
Uses & applications
Widely used in construction as crushed aggregate for road bases, concrete production, and railroad ballast, as well as in stonework.
Geological facts
Basalt is the most common rock type in the Earth's crust underlying the world's oceans, and it also forms massive volcanic structures like the Giant's Causeway.
Field identification & locations
Identify in the field by its dark, heavy, fine-grained appearance, often showing small vesicles or mineral crystals; found globally in volcanic regions.
