sedimentary

Quartz-rich sandstone or quartzite pebble

Granular quartz (SiO₂), possibly with minor feldspar or carbonate cement

AI-generated identification · may be incorrect

Cream to pale tan, rounded and weathered, with a sugary granular texture and dull to slightly vitreous luster. Quartz hardness is 7 Mohs; individual grains show no obvious cleavage, and specific gravity is about 2.65.

Identified September 10, 2026More sedimentary →

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Physical properties

Formation & geological history

Most likely a water-worn sedimentary pebble formed from cemented quartz sand; if strongly recrystallized, it may be quartzite (metamorphic). Exact age and formation locality cannot be determined from the photograph.

Uses & applications

Common sandstone is used as building stone, aggregate, and paving; quartzite is used for durable construction stone, countertops, and decorative specimens. This pebble has modest collector value.

Geological facts

The rounded shape indicates transport by stream, wave, or glacial action. A glassy scratch test can help distinguish quartz-rich material from softer carbonate rocks.

Field identification & locations

Look for visible sand grains, weak cement, and scratching of glass; quartzite typically has tightly fused grains and breaks across them. Common worldwide in riverbeds, beaches, and glacial deposits.