igneous
Basalt
Extrusive igneous rock
AI-generated identification · may be incorrectHardness 6 on Mohs scale, dark gray to black color, dull luster, fine-grained aphanitic crystal structure, high specific gravity.
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 6 on Mohs scale, dark gray to black color, dull luster, fine-grained aphanitic crystal structure, high specific gravity.
Formation & geological history
Formed from the rapid cooling of low-viscosity, magnesium- and iron-rich lava exposed at or very near the Earth's surface.
Uses & applications
Commonly used in construction aggregate, railroad ballast, road base, and crushed stone.
Geological facts
Basalt is the most common rock type in the Earth's crust underlying the world's oceans.
Field identification & locations
Identify by its dark, fine-grained appearance, often found in volcanic regions, oceanic crust, and flood basalt provinces globally.
