metamorphic
Coarse-grained gray metamorphic rock, likely gneiss
Biotite–quartz–feldspar gneiss (probable)
AI-generated identification · may be incorrectHardness about 6–7; gray, white, and dark flecked appearance with a granular texture and possible weak foliation. Likely vitreous to dull luster; quartz and feldspar show poor cleavage, while mica has one perfect cleavage; density commonly 2.6–2.8 g/cm³.
Identified More metamorphic →
Explore Coarse-grained gray metamorphic rock, likely gneiss in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness about 6–7; gray, white, and dark flecked appearance with a granular texture and possible weak foliation. Likely vitreous to dull luster; quartz and feldspar show poor cleavage, while mica has one perfect cleavage; density commonly 2.6–2.8 g/cm³.
Formation & geological history
Formed when granitic or sedimentary rock underwent intense heat and pressure, producing recrystallization and mineral banding; commonly Precambrian to younger. The blurred image prevents confident mineral or rock identification.
Uses & applications
Used as dimension stone, paving, aggregate, landscaping material, and occasionally as a decorative specimen; generally not a jewelry stone.
Geological facts
The light grains are likely quartz and feldspar, while dark grains may be biotite or amphibole. Strong alternating light-dark bands would support gneiss; a massive, nonbanded texture could instead indicate granite or granodiorite.
Field identification & locations
Common in continental shields and high-grade metamorphic terrains worldwide. Examine a fresh surface for visible quartz, feldspar, mica, and foliation; a streak, hardness, and close-up photo would improve identification.
More like this
