mineral

Botryoidal chalcedony (likely moss or plume agate)

Microcrystalline quartz, SiO₂; chalcedony with possible iron/manganese inclusions

AI-generated identification · may be incorrect

Hardness 6.5–7; pale gray, cream, and brown with rounded botryoidal textures; waxy to dull luster; cryptocrystalline quartz with no visible cleavage; specific gravity about 2.6.

Identified September 22, 2026More mineral →

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At a glance

Common name: Botryoidal chalcedony (likely moss or plume agate)
Scientific name: Microcrystalline quartz, SiO₂; chalcedony with possible iron/manganese inclusions
Category: mineral
Identified: September 22, 2026
Method: Standard

AI Estimated Value

About $3–$15 for a small rough packaged specimen; $20–$100+ if the pattern, polish, and translucency are notably attractive.

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

Hardness 6.5–7; pale gray, cream, and brown with rounded botryoidal textures; waxy to dull luster; cryptocrystalline quartz with no visible cleavage; specific gravity about 2.6.

Formation & geological history

Forms when silica-rich groundwater fills cavities and fractures in volcanic rock, depositing layers of chalcedony; commonly Cenozoic to older volcanic-hosted material. The precise variety cannot be confirmed from the packaged image.

Uses & applications

Used for cabochons, carvings, tumbled stones, display specimens, and lapidary work; generally decorative rather than industrial.

Geological facts

Botryoidal means grape-like rounded surfaces. Brown coloration commonly comes from iron oxides, while branching or plume-like patterns may reflect mineral inclusions.

Field identification & locations

Identify by its very fine-grained, waxy appearance, conchoidal fracture, and hardness sufficient to scratch ordinary glass; it is not crystalline calcite or soft concrete. Common sources include Oregon, Montana, Indonesia, Brazil, and Mexico.