igneous
Basalt
Extrusive Igneous Rock
Hardness: 6 on Mohs scale, Color: Dark grey to black, Luster: Dull or sub-metallic, Crystal structure: Aphanitic (fine-grained), Cleavage: None, Specific Gravity: 2.8-3.0
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Physical properties
Hardness: 6 on Mohs scale, Color: Dark grey to black, Luster: Dull or sub-metallic, Crystal structure: Aphanitic (fine-grained), Cleavage: None, Specific Gravity: 2.8-3.0
Formation & geological history
Formed from the rapid cooling of low-viscosity lava rich in iron and magnesium exposed at or very near the surface of a planet or moon.
Uses & applications
Used in construction, aggregate for roads, making railroad ballast, and manufacturing of stone wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's crust underlying the ocean basins, and it is also found extensively on the Moon and Mars.
Field identification & locations
Identify by its dark, fine-grained, heavy nature, often showing vesicular (gas bubble) textures. Commonly found in volcanic regions worldwide.
