mineral

Polished yellow-brown chalcedony (likely carnelian or mossy/iron-stained agate)

Microcrystalline quartz, SiO₂; chalcedony with iron-oxide inclusions

AI-generated identification · may be incorrect

Hardness 6.5–7 Mohs; translucent honey-yellow to brown with reddish iron staining, waxy-to-glassy luster, cryptocrystalline quartz, and no visible cleavage. The rounded, glossy surface indicates tumbling or polishing.

Identified September 15, 2026More mineral →

Explore Polished yellow-brown chalcedony (likely carnelian or mossy/iron-stained agate) in the encyclopedia →

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At a glance

Common name: Polished yellow-brown chalcedony (likely carnelian or mossy/iron-stained agate)
Scientific name: Microcrystalline quartz, SiO₂; chalcedony with iron-oxide inclusions
Category: mineral
Identified: September 15, 2026
Method: Standard

AI Estimated Value

Approximately $5–$25 for a common polished piece; $30–$100+ if unusually translucent, attractive, 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

Forms when silica-rich groundwater fills cavities and fractures, commonly in volcanic rocks; iron oxides create the brown-red coloration. Deposition is generally Cenozoic to older, depending on the host formation.

Uses & applications

Used as an ornamental stone, cabochon, bead, carving, and inexpensive jewelry material; polished specimens are commonly collected.

Geological facts

Carnelian is orange-red chalcedony, while agate usually shows banding or moss-like inclusions; this specimen’s lack of obvious banding makes an exact variety uncertain from the image alone.

Field identification & locations

Common in volcanic terrains and alluvial gravels, including India, Brazil, Uruguay, Madagascar, and the western United States. Identification is supported by its glassy translucence, high scratch resistance, and conchoidal fracture; it should not scratch easily with a steel nail.