metamorphic

Tumbled brown quartzite or chert pebble

Quartzite, primarily microcrystalline SiO₂; exact identification is uncertain from the photograph

AI-generated identification · may be incorrect

Hardness about 7 Mohs, brown to tan mottling, opaque, and waxy to subvitreous luster. Dense, fine-grained, and smoothly rounded from natural abrasion or tumbling; cleavage absent and fracture conchoidal to irregular.

Identified September 14, 2026More metamorphic →

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At a glance

Common name: Tumbled brown quartzite or chert pebble
Scientific name: Quartzite, primarily microcrystalline SiO₂; exact identification is uncertain from the photograph
Category: metamorphic
Identified: September 14, 2026
Method: Standard

AI Estimated Value

About $1-$10 for a common tumbled pebble; $10-$30 if unusually patterned, large, or sold as a curated lapidary specimen.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

Quartzite forms when quartz-rich sandstone is recrystallized under heat and pressure, commonly during mountain-building; its age depends on the source formation. The rounded shape indicates stream, beach, or deliberate lapidary abrasion.

Uses & applications

Used as aggregate, building stone, paving material, and landscaping rock; attractive pieces are sold as polished or tumbled specimens. Typical small specimens have modest collector value.

Geological facts

The surface texture and brown coloration could also indicate iron-stained chert or jasper, which are difficult to distinguish visually. A streak, hardness, and specific-gravity test would help separate these materials.

Field identification & locations

Common in river gravels and glacial deposits worldwide, especially near quartz-rich metamorphic belts. It should scratch glass and resist scratching by a steel knife; a white streak would support quartzite rather than iron-rich minerals.