metamorphic
Gneiss
Gneiss
AI-generated identification · may be incorrectHardness of 6-7 on Mohs scale, characterized by distinct alternating light and dark compositional banding (gneissic banding). Exhibits a granular texture with vitreous luster.
Identified More metamorphic →
Explore Gneiss in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness of 6-7 on Mohs scale, characterized by distinct alternating light and dark compositional banding (gneissic banding). Exhibits a granular texture with vitreous luster.
Formation & geological history
Formed through high-grade regional metamorphism of preexisting igneous or sedimentary rocks under extreme heat and pressure deep within the Earth's crust.
Uses & applications
Used primarily in the construction industry as crushed stone for road bases, building facades, and dimension stone.
Geological facts
Gneiss contains some of the oldest known rock material on Earth, with certain formations dating back over 4 billion years.
Field identification & locations
Identified by its zebra-like alternating bands of light quartz/feldspar and dark biotite/hornblende. Common in ancient continental shields worldwide.
More like this
