gemstone

Polished dendritic agate cabochon

Microcrystalline quartz (chalcedony), SiO₂, with iron/manganese dendrites and possible plume inclusions

AI-generated identification · may be incorrect

Translucent gray-blue to brown chalcedony with white, mossy/plume-like inclusions and a vitreous-to-waxy luster; hardness about 6.5–7 Mohs, cryptocrystalline structure, no cleavage, specific gravity about 2.60. The domed cabochon is set in a metal ring.

Identified August 28, 2026More gemstone →

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At a glance

Common name: Polished dendritic agate cabochon
Scientific name: Microcrystalline quartz (chalcedony), SiO₂, with iron/manganese dendrites and possible plume inclusions
Category: gemstone
Identified: August 28, 2026
Method: Standard

AI Estimated Value

Approximately $15–$75 for a commercial ring; $75–$250 if the pattern, workmanship, and silver setting are notably high quality.

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

Silica-rich groundwater filled cavities in volcanic rocks, where chalcedony precipitated in layers; dendritic oxides formed branching inclusions during growth. Agates commonly formed in Paleozoic–Cenozoic volcanic terrains, though this specimen’s exact age is unknowable from the image.

Uses & applications

Used for cabochons, rings, beads, carvings, and ornamental objects; valued mainly for attractive pattern and translucency.

Geological facts

Dendritic patterns are mineral inclusions, not plant fossils. The metal setting and polished surface indicate a finished jewelry specimen.

Field identification & locations

Identify by translucency, very fine texture, curved banding or plume/dendrite patterns, and inability to scratch it with a fingernail or steel knife. Common sources include Brazil, Uruguay, India, Mexico, Madagascar, and the United States.