metamorphic
Weathered quartz pebble (probable quartzite)
Quartz (SiO₂); possibly quartzite, a metamorphosed quartz-rich sandstone
AI-generated identification · may be incorrectPale gray-white, rounded, and dull to weakly vitreous; likely hardness ~7 Mohs, no obvious cleavage, conchoidal fracture, and specific gravity near 2.65. The granular texture suggests quartzite rather than a single crystal.
Identified More metamorphic →
Explore Weathered quartz pebble (probable quartzite) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Pale gray-white, rounded, and dull to weakly vitreous; likely hardness ~7 Mohs, no obvious cleavage, conchoidal fracture, and specific gravity near 2.65. The granular texture suggests quartzite rather than a single crystal.
Formation & geological history
Likely eroded from quartz-rich metamorphic or vein material and transported to the beach; quartzite forms by burial, heating, and pressure acting on sandstone, commonly during mountain-building events. Its exact geological age cannot be determined from the image.
Uses & applications
Common quartzite is used as aggregate, road stone, building stone, and landscaping material; attractive pieces may be collected but are generally not jewelry grade.
Geological facts
Quartz is one of Earth’s most abundant minerals and resists weathering, allowing it to persist as rounded beach pebbles. The bright surface may reflect a fresh fracture or abrasion.
Field identification & locations
Test with a steel knife or glass: quartz should resist scratching and scratch glass, though surface coatings can mislead. Look for interlocking granular quartz, absence of fizz in dilute acid, and no strong cleavage; common on beaches, river gravels, and quartz-rich terrains.
More like this
