igneous
Basalt
Extrusive igneous rock
AI-generated identification · may be incorrectHardness 6 on the Mohs scale, dark gray to black color, fine-grained aphanitic 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 6 on the Mohs scale, dark gray to black color, fine-grained aphanitic texture, and dull luster.
Formation & geological history
Formed from the rapid cooling of low-viscosity lava flows rich in iron and magnesium at the Earth's surface.
Uses & applications
Used extensively in construction as crushed stone for road bases, concrete aggregate, and in the manufacturing of rock wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's crustal portions underlying the ocean basins and forms famous formations like the Giant's Causeway.
Field identification & locations
Identify in the field by its dark color, heavy feel, and fine-grained texture; commonly found in volcanic regions worldwide.
