igneous
Weathered quartz-rich pebble
Likely milky quartz or quartzite (SiO₂), possibly a weathered feldspathic rock
AI-generated identification · may be incorrectOff-white, opaque, fine- to medium-grained pebble with dull to weakly vitreous luster and brown surface staining; quartz hardness is about 7 Mohs, with no obvious cleavage. Exact identification is limited by the small, weathered specimen and photograph.
Identified More igneous →
Explore Weathered quartz-rich pebble in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Off-white, opaque, fine- to medium-grained pebble with dull to weakly vitreous luster and brown surface staining; quartz hardness is about 7 Mohs, with no obvious cleavage. Exact identification is limited by the small, weathered specimen and photograph.
Formation & geological history
Likely eroded from quartz vein material, quartzite, or a silica-rich igneous rock and rounded by stream or beach transport; its geological age cannot be determined visually. Iron-oxide staining accounts for the brown patches.
Uses & applications
Common pebbles have little commercial value, though quartzite is used as aggregate, landscaping stone, and construction material; attractive pieces may be collected or tumbled.
Geological facts
Quartz commonly forms durable white pebbles because it resists chemical and physical weathering. A glass-scratch test can help distinguish quartz from softer white minerals, but it may damage the specimen.
Field identification & locations
Look for glassy fracture, lack of cleavage, and inability to scratch it with a steel nail; quartzite may show fused granular texture, while feldspar is softer and often cleaves. Common worldwide in streambeds, beaches, and glacial deposits.
