mineral

Tumbled yellow chalcedony (likely silicified material)

Microcrystalline quartz, SiO₂; possibly iron-stained chalcedony or fossilized/silicified limestone

AI-generated identification · may be incorrect

Hardness about 6.5–7, pale honey-yellow, waxy to dull luster, cryptocrystalline quartz with no visible cleavage; rounded and polished/tumbled. The small pits and mottling may reflect weathering, inclusions, or dissolved fossil grains.

Identified September 8, 2026More mineral →

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At a glance

Common name: Tumbled yellow chalcedony (likely silicified material)
Scientific name: Microcrystalline quartz, SiO₂; possibly iron-stained chalcedony or fossilized/silicified limestone
Category: mineral
Identified: September 8, 2026
Method: Standard

AI Estimated Value

About $2–$15 for a common tumbled piece; $20–$75 if it proves to be attractive fossiliferous or unusual material.

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

Chalcedony forms when silica-rich groundwater fills cavities and fractures, commonly in volcanic rocks or sedimentary deposits; yellow color usually comes from iron oxides. Exact geological age and identity cannot be determined from the photograph alone.

Uses & applications

Used as a lapidary stone, cabochon, bead, or decorative specimen; ordinary pieces have modest value.

Geological facts

A glassy scratch test is useful: chalcedony should scratch ordinary glass, though surface polish can complicate testing. Acid fizzing would suggest calcite rather than quartz, while a steel point should not scratch chalcedony.

Field identification & locations

Commonly found in silica-rich gravels, volcanic cavities, and sedimentary beds worldwide; examine translucency, conchoidal fracture, hardness, and absence of cleavage. The specimen appears human-tumbled.