igneous
Basalt
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 luster.
Identified More igneous →
Explore Basalt in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
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 luster.
Formation & geological history
Formed from the rapid cooling of low-viscosity lava rich in iron and magnesium exposed at or very near the Earth's surface.
Uses & applications
Widely used in construction as crushed aggregate for road bases, concrete production, and in manufacturing stone wool insulation.
Geological facts
Basalt is the most common rock type on Earth's crust, primarily making up the ocean floors and forming massive plateau structures like the Columbia River Basalts.
Field identification & locations
Identify by its dark, fine-grained appearance, often containing tiny visible crystals of plagioclase or olivine; commonly found in volcanic regions worldwide.
