igneous
Basalt Pebble
Extrusive Igneous Rock
Hardness of 6 on the Mohs scale; dark gray to black color; fine-grained, aphanitic texture; dull luster; specific gravity around 2.8-3.0.
Identified More igneous →
Explore Basalt Pebble 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; fine-grained, aphanitic texture; dull luster; specific gravity around 2.8-3.0.
Formation & geological history
Formed from the rapid cooling of low-viscosity lava rich in magnesium and iron, exposed at or very near the surface of a planet or moon.
Uses & applications
Used in construction as crushed stone for road bases, concrete aggregate, and railroad ballast, as well as in stonemasonry.
Geological facts
Basalt is the most common rock type in the Earth's crust underlying the ocean basins and is also found abundantly on the Moon, Mars, and Venus.
Field identification & locations
Easily identified by its dark, dense, and fine-grained appearance, often found smoothly water-worn in riverbeds and beaches.
