metamorphic
Gneiss
Gneiss
AI-generated identification · may be incorrectHardness 6-7 on Mohs scale, characterized by distinct alternating light and dark compositional bands (gneissic banding). Exhibits a granular, foliated crystal structure with a vitreous to dull 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 6-7 on Mohs scale, characterized by distinct alternating light and dark compositional bands (gneissic banding). Exhibits a granular, foliated crystal structure with a vitreous to dull luster.
Formation & geological history
Formed through high-grade regional metamorphism of preexisting igneous or sedimentary rocks under extreme temperatures and pressures deep within the Earth's crust.
Uses & applications
Used primarily in the construction industry as crushed stone for road bases, building facades, and monumental stone.
Geological facts
Some of the oldest known rocks on Earth, dating back over 4 billion years, are classified as gneiss.
Field identification & locations
Identified in the field by its striking zebra-like light and dark mineral bands, commonly found in ancient continental shields.
More like this
