igneous
Basalt
Extrusive Igneous Rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, dark gray to black color, aphanitic texture with a dull luster, and high specific gravity around 2.9.
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, dark gray to black color, aphanitic texture with a dull luster, and high specific gravity around 2.9.
Formation & geological history
Formed from the rapid cooling of low-viscosity lava rich in magnesium and iron exposed at the surface of a planet or moon.
Uses & applications
Commonly used in construction as crushed aggregate for roads, railroad ballast, and in the manufacturing of rock wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's crust underlying the world's ocean basins and forming massive volcanic formations like the Columbia River Basalts.
Field identification & locations
Identified by its fine-grained dark appearance and heavy weight, frequently collected in volcanic regions and oceanic islands.
