metamorphic
Weathered quartz-rich rock, possibly quartzite or granitic pegmatite fragment
Quartz (SiO₂)-dominant aggregate; exact identification is uncertain from the photograph
AI-generated identification · may be incorrectPale gray-beige, coarse granular texture with a vitreous to dull luster and apparent interlocking translucent grains; quartz hardness is Mohs 7, with no obvious cleavage. The porous dark cavities may reflect weathering or inclusions, but crystal form and density are not diagnostic here.
Identified More metamorphic →
Explore Weathered quartz-rich rock, possibly quartzite or granitic pegmatite fragment in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Pale gray-beige, coarse granular texture with a vitreous to dull luster and apparent interlocking translucent grains; quartz hardness is Mohs 7, with no obvious cleavage. The porous dark cavities may reflect weathering or inclusions, but crystal form and density are not diagnostic here.
Formation & geological history
If quartzite, it formed by metamorphism of quartz sandstone under heat and pressure; if pegmatitic, it crystallized from a late-stage silica-rich igneous melt. A geological age cannot be determined visually.
Uses & applications
Quartzite is used as aggregate, building stone, and occasional lapidary material; attractive pieces may be polished, though this specimen appears mostly of modest decorative or educational value.
Geological facts
Quartz-rich rocks commonly contain minor feldspar, mica, iron oxides, or sulfides that produce gray, tan, and dark patches. A steel file should not scratch exposed quartz grains, while glass can usually be scratched.
Field identification & locations
Common in metamorphic terrains and gravel deposits worldwide. Confirm with a fresh surface, hardness test, streak, and ideally acid testing or thin-section analysis; the photograph alone cannot distinguish quartzite from weathered pegmatite confidently.
More like this
