igneous
Weathered granite or granitic gneiss
Granite/granitic gneiss; chiefly quartz, feldspar, and mica
AI-generated identification · may be incorrectCoarse, massive specimen with gray, pink, and whitish mottling; likely glassy quartz, feldspar, and dark mica. Mohs hardness about 6–7, nonmetallic luster, poor or absent cleavage as a rock, and typical specific gravity around 2.6–2.7.
Identified More igneous →
Explore Weathered granite or granitic gneiss in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Coarse, massive specimen with gray, pink, and whitish mottling; likely glassy quartz, feldspar, and dark mica. Mohs hardness about 6–7, nonmetallic luster, poor or absent cleavage as a rock, and typical specific gravity around 2.6–2.7.
Formation & geological history
Likely formed from slowly cooled silica-rich magma, or from metamorphosed granite if the faint streaking is foliation. Such rocks range from Precambrian to recent geological ages and commonly occur in continental mountain belts and glacial deposits.
Uses & applications
Used as crushed aggregate, building stone, monuments, countertops, and landscaping rock; this ordinary weathered piece has little jewelry value.
Geological facts
The pink coloration usually comes from potassium feldspar, while gray translucent areas may be quartz. The image does not show enough detail to distinguish granite confidently from gneiss or another feldspathic rock.
Field identification & locations
Identify it by its visible interlocking grains, hardness, and lack of reaction to dilute acid; a streaked texture and aligned minerals would favor gneiss. Common worldwide, especially in shields, mountain ranges, and transported boulders.
