igneous
Basalt Pebble
Aphanitic Igneous Rock
AI-generated identification · may be incorrectHardness of 6 on Mohs scale; dark gray to black color; dull to sub-vitreous luster; fine-grained, microcrystalline structure.
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 Mohs scale; dark gray to black color; dull to sub-vitreous luster; fine-grained, microcrystalline structure.
Formation & geological history
Formed from the rapid cooling of low-viscosity, mafic lava flows at or near the Earth's surface. Ubiquitous in oceanic crust.
Uses & applications
Used widely in construction as crushed aggregate, railroad ballast, and dimension stone.
Geological facts
Basalt is the most common rock type in the Earth's crust and makes up most of the ocean floors as well as planetary bodies like the Moon and Mars.
Field identification & locations
Identified by its dark color, heavy feel, and very fine-grained texture lacking visible crystals; commonly found in riverbeds and beaches.
