metamorphic
Banded Gneiss
Gneiss (High-grade Metamorphic Rock)
Hardness: 6-7 (Mohs scale), Color: Dark grey matrix with white/cream bands, Luster: Dull to vitreous, Structure: Foliated with distinct mineral banding (gneissose banding), Cleavage: Poor.
Identified More metamorphic →
Explore Banded Gneiss in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 (Mohs scale), Color: Dark grey matrix with white/cream bands, Luster: Dull to vitreous, Structure: Foliated with distinct mineral banding (gneissose banding), Cleavage: Poor.
Formation & geological history
Formed through high-pressure, high-temperature metamorphism of igneous or sedimentary rocks. The bands are created by mineral segregation during intense tectonic stress over millions of years.
Uses & applications
Used primarily as decorative stone in landscaping, crushed stone for road construction, and occasionally for high-quality building facades or interior flooring.
Geological facts
Gneiss contains some of the oldest known crustal rocks on Earth, such as the Acasta Gneiss which is approximately 4 billion years old.
Field identification & locations
Identify in the field by looking for distinct layers of light and dark minerals that are often folded or wavy. Found in mountainous regions and tectonic shield areas. Common in glacial till.
More like this
