mineral

Botryoidal chalcedony (likely quartz with iron staining)

Chalcedony, cryptocrystalline SiO₂; possible quartz druse and limonite/goethite inclusions

AI-generated identification · may be incorrect

Usually hardness 6.5–7 Mohs, translucent white to cream with yellow-brown staining, and waxy to vitreous luster; commonly forms rounded botryoidal masses rather than distinct crystals. The granular sparkling areas are likely drusy quartz.

Identified September 16, 2026More mineral →

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At a glance

Common name: Botryoidal chalcedony (likely quartz with iron staining)
Scientific name: Chalcedony, cryptocrystalline SiO₂; possible quartz druse and limonite/goethite inclusions
Category: mineral
Identified: September 16, 2026
Method: Standard

AI Estimated Value

About $10–$50 for a small common specimen; $50–$150+ if locality-documented, unusually attractive, or strongly drusy.

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 in volcanic rocks, precipitating chalcedony and later quartz coatings; iron oxides produce the brown-yellow colors. Exact age and locality cannot be determined from the image.

Uses & applications

Used as a lapidary and ornamental material, in cabochons and carvings, and as a collectible mineral specimen; not generally important for construction.

Geological facts

Botryoidal means grape-like rounded growths. Chalcedony is a microcrystalline variety of quartz, and its colors commonly result from trace iron or other impurities.

Field identification & locations

Look for curved botryoidal surfaces, waxy translucency, conchoidal fracture, and hardness sufficient to scratch glass; acid produces no reaction. Common in volcanic districts worldwide, including Brazil, Uruguay, Mexico, India, and the western United States.