metamorphic
Gneiss
Gneiss
AI-generated identification · may be incorrectHardness of 6-7 on Mohs scale, characterized by distinct alternating light and dark compositional banding. It exhibits a vitreous to sub-pearly luster with a foliated structure.
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. It exhibits a vitreous to sub-pearly luster with a foliated structure.
Formation & geological history
Formed through high-grade regional metamorphism of pre-existing igneous or sedimentary rocks under extreme heat and pressure, typically during mountain-building events.
Uses & applications
Used primarily in the construction industry as crushed stone for road bases, building facades, and dimension stone.
Geological facts
Gneiss is one of the oldest rocks on Earth, with some specimens dating back over 4 billion years.
Field identification & locations
Easily identified in the field by its striking zebra-like banding known as gneissic banding. Found globally in ancient continental shields.
More like this
