igneous
Scoria (Lava Rock)
Vesicular Basalt / Scoria
Dark brown to black color, highly vesicular texture full of small cavities (vesicles), dull/earthy luster, Mohs hardness 5-6, glassy to aphanitic groundmass.
Identified More igneous →
Explore Scoria (Lava Rock) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Dark brown to black color, highly vesicular texture full of small cavities (vesicles), dull/earthy luster, Mohs hardness 5-6, glassy to aphanitic groundmass.
Formation & geological history
Formed during explosive volcanic eruptions when gas-rich basaltic or andesitic lava cools rapidly, trapping expanding gas bubbles inside as it solidifies.
Uses & applications
Used widely in landscaping, barbecue grills, lightweight concrete aggregates, road construction, and drainage filtration systems.
Geological facts
Scoria is so full of air pockets that it is very lightweight, though unlike pumice, it usually sinks in water due to thicker cell walls and higher density iron/magnesium content.
Field identification & locations
Identified field-side by its dark color, lightweight feel, and sponge-like vesicular texture. Commonly found in volcanic regions, near cinder cones and basaltic flows around the world.
