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 an aphanitic or fine-grained crystal structure 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 crystal structure and dull luster.
Formation & geological history
Formed from the rapid cooling of low-viscosity, magnesium- and iron-rich lava flows on the Earth's surface.
Uses & applications
Widely used in construction as crushed stone for road bases, aggregate in concrete, 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 forms massive volcanic structures like the Giant's Causeway.
Field identification & locations
Identify in the field by its dark, fine-grained matrix, often found in volcanic regions and ancient lava plateaus worldwide.
