mineral

Tumbled chalcedony or quartzite pebble

Microcrystalline quartz (SiO₂), likely chalcedony; exact identification requires testing

AI-generated identification · may be incorrect

Pale cream to yellow-brown, waxy to dull luster, massive microcrystalline texture, and irregular fractures; quartz hardness is about 7 Mohs and specific gravity about 2.6. The rounded shape indicates natural water wear or tumbling, with darker inclusions or surface staining.

Identified August 19, 2026More mineral →

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At a glance

Common name: Tumbled chalcedony or quartzite pebble
Scientific name: Microcrystalline quartz (SiO₂), likely chalcedony; exact identification requires testing
Category: mineral
Identified: August 19, 2026
Method: Standard

AI Estimated Value

Usually $1-$10 as a small tumbled or common rough specimen; approximately $10-$30 if unusually attractive, translucent, or distinctly patterned.

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

Formed when silica-rich fluids filled cavities or fractures, or as a quartz-rich metamorphic clast later rounded by erosion; age is locality-dependent, commonly Paleozoic or younger. The image alone cannot establish its precise geological history.

Uses & applications

Used as an ornamental and lapidary stone, for cabochons, carvings, polished pebbles, and inexpensive collectibles; quartz-rich aggregate may also be used in construction.

Geological facts

Chalcedony is quartz whose crystals are too small to see unaided; yellow or brown colors commonly result from iron staining. It may be confused with jasper, common quartzite, or weathered limestone.

Field identification & locations

Look for a glassy-to-waxy surface, translucent edges, conchoidal fracture, and resistance to scratching by a steel knife; it should not scratch glass reliably if heavily weathered or porous. Common in river gravels and silica-rich volcanic or sedimentary terrains.