mineral

Quartz geode (likely chalcedony-lined geode)

Silica geode: microcrystalline quartz/chalcedony with drusy quartz (SiO₂), possibly iron-oxide staining

AI-generated identification · may be incorrect

Hardness 6.5–7 Mohs; white to translucent gray quartz crystals with cream-orange, iron-stained chalcedony and earthy matrix. Vitreous to waxy luster, trigonal quartz structure, conchoidal fracture, and no obvious cleavage; typical specific gravity is about 2.65.

Identified September 4, 2026More mineral →

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At a glance

Common name: Quartz geode (likely chalcedony-lined geode)
Scientific name: Silica geode: microcrystalline quartz/chalcedony with drusy quartz (SiO₂), possibly iron-oxide staining
Category: mineral
Identified: September 4, 2026
Method: Standard

AI Estimated Value

About $15–$75 for a common hand-sized specimen; $100–$300+ if unusually large, vividly colored, or exceptionally well crystallized.

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 in volcanic rock or sedimentary concretions, depositing chalcedony first and quartz crystals later. Individual geodes commonly formed during Cenozoic to older volcanic or sedimentary episodes, depending on locality.

Uses & applications

Used as a decorative specimen, paperweight, and lapidary material; attractive crystal-lined cavities have modest collector value. It is not generally used as construction stone.

Geological facts

The hollow cavity and crystal lining are diagnostic of a geode; orange coloration is commonly goethite or hematite staining rather than orange quartz. The outer rind appears weathered and iron-rich.

Field identification & locations

Identify by a hard, silica-rich rind surrounding an open cavity lined with sparkly quartz or chalcedony; common sources include Brazil, Uruguay, Mexico, Morocco, and the western United States. A steel file should not easily scratch quartz.