metamorphic
Banded metamorphic rock, likely gneiss
Foliated quartz–feldspar rock (gneiss; exact identification requires closer examination)
AI-generated identification · may be incorrectGray, pink, and pale bands with a granular, foliated texture; likely quartz and feldspar with mica. Typical gneiss has Mohs hardness around 6–7, vitreous to dull luster, and no prominent cleavage as a whole rock.
Identified More metamorphic →
Explore Banded metamorphic rock, likely gneiss in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Gray, pink, and pale bands with a granular, foliated texture; likely quartz and feldspar with mica. Typical gneiss has Mohs hardness around 6–7, vitreous to dull luster, and no prominent cleavage as a whole rock.
Formation & geological history
Forms when pre-existing rock is recrystallized under high heat and pressure, commonly deep in continental crust; the specimen’s age cannot be determined from the image.
Uses & applications
Gneiss is used as dimension stone, crushed aggregate, landscaping stone, and occasionally as a decorative building material.
Geological facts
Alternating light and dark mineral bands are called gneissic banding and reflect mineral segregation during metamorphism.
Field identification & locations
Look for coarse grains and distinct, roughly parallel light and dark bands; similar rocks occur in ancient metamorphic terrains worldwide. The small rough specimen has limited commercial value.
More like this
Other metamorphic specimens
Nephrite Jade
Nephrite
Mineral/Rock
Amphibolite
Amphibolite
metamorphic
Rhodonite
Manganese Silicate (Mn, Fe, Mg, Ca)SiO3
mineral
Rhodonite
(Mn,Fe,Mg,Ca)SiO3
mineral
Greenschist
Greenschist (containing Chlorite, Actinolite, and Epidote)
metamorphic
Garnet
Garnet group: X3Y2(SiO4)3 (commonly Almandine-Pyrope series)
mineral