mineral

Polished chalcedony (likely moss or dendritic agate)

Microcrystalline quartz, SiO₂; chalcedony with possible iron-oxide and/or manganese dendrites

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; translucent gray-white to honey-brown with yellow-brown inclusions, waxy-to-glassy luster, cryptocrystalline quartz structure, and no visible cleavage. The smoothly polished surface obscures natural texture and makes exact identification uncertain from the image alone.

Identified September 6, 2026More mineral →

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At a glance

Common name: Polished chalcedony (likely moss or dendritic agate)
Scientific name: Microcrystalline quartz, SiO₂; chalcedony with possible iron-oxide and/or manganese dendrites
Category: mineral
Identified: September 6, 2026
Method: Standard

AI Estimated Value

About $5–$30 for a small common polished piece; $40–$150+ for unusually attractive, translucent patterns or quality cabochon 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

Forms when silica-rich groundwater fills cavities and fractures, depositing chalcedony in volcanic rocks; colored patterns commonly result from iron or manganese oxides. Deposits range from Paleozoic to recent, depending on locality.

Uses & applications

Used for cabochons, beads, carvings, and ornamental objects; attractive patterned pieces have modest jewelry and collector value.

Geological facts

Moss agate patterns are mineral inclusions rather than plant fossils. A scratch test against glass and examination under magnification can help distinguish chalcedony from jasper or common glass.

Field identification & locations

Commonly found in volcanic terrains, especially India, Brazil, Uruguay, Madagascar, Mexico, and the western United States. Look for waxy luster, conchoidal fracture, translucency, and hardness greater than ordinary glass.