metamorphic
Quartz-rich rock, likely quartzite or quartz vein fragment
Quartz (SiO₂), possibly with iron-oxide staining and minor feldspar/mica
AI-generated identification · may be incorrectHardness about 7 Mohs; pale tan to gray, granular and translucent in places, with a vitreous to dull luster. Interlocking quartz grains and lacking obvious cleavage suggest quartzite, though the photograph cannot distinguish it confidently from massive vein quartz.
Identified More metamorphic →
Explore Quartz-rich rock, likely quartzite or quartz vein fragment in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness about 7 Mohs; pale tan to gray, granular and translucent in places, with a vitreous to dull luster. Interlocking quartz grains and lacking obvious cleavage suggest quartzite, though the photograph cannot distinguish it confidently from massive vein quartz.
Formation & geological history
Quartzite forms when sandstone is metamorphosed under heat and pressure; vein quartz precipitates from silica-rich hydrothermal fluids. The specimen’s precise age and locality cannot be determined visually.
Uses & applications
Common quartzite is used as aggregate, building stone, paving material, and sometimes decorative stone; attractive quartz-rich pieces are collected but generally have little gem value.
Geological facts
Quartz is one of Earth’s most abundant minerals and is highly resistant to weathering, allowing quartz-rich rocks to survive as durable sediment and resistant outcrops.
Field identification & locations
Test with a steel knife or glass: quartz-rich material should scratch glass and resist a knife. A streak test is usually white; iron staining commonly produces the tan-brown color. Common worldwide, especially in metamorphic belts and hydrothermal veins.
More like this
