igneous
Basalt Pebble
Extrusive Igneous Rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, dark gray to black color, dull to sub-withering luster, aphanitic crystal structure, and high density.
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, dull to sub-withering luster, aphanitic crystal structure, and high density.
Formation & geological history
Formed from the rapid cooling of low-viscosity basaltic lava exposed at or very near the Earth's surface.
Uses & applications
Used extensively in construction as crushed aggregate, railroad ballast, and in the production of stone wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's crust underlying the world's ocean basins and forms prominent geological formations like the Giant's Causeway.
Field identification & locations
Easily identified in the field by its dark, fine-grained matrix and smooth water-worn shape when found in riverbeds or beaches.
