mineral

Quartz geode fragment

Microcrystalline quartz (SiO₂), possibly with iron-oxide staining or an unidentified dark mineral inclusion

AI-generated identification · may be incorrect

Hardness about 7 Mohs; white to translucent, dull-to-glassy luster, irregular fracture, and no obvious cleavage. The rounded, cut-open piece appears to have a pale chalcedony/quartz rind surrounding a darker cavity or inclusion.

Identified August 26, 2026More mineral →

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At a glance

Common name: Quartz geode fragment
Scientific name: Microcrystalline quartz (SiO₂), possibly with iron-oxide staining or an unidentified dark mineral inclusion
Category: mineral
Identified: August 26, 2026
Method: Standard

AI Estimated Value

About $2–$15 for a small common fragment; higher only if the interior contains unusually attractive crystals or confirmed rare minerals.

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

Likely formed when silica-rich groundwater filled a vesicle or cavity in volcanic rock, depositing chalcedony and later quartz; the specimen’s exact geological age and locality cannot be determined from the image. It may also be a small agate/geode nodule that was cut or broken open.

Uses & applications

Used as a decorative and collecting specimen; attractive quartz or agate interiors may be used in jewelry, cabochons, and carvings. This small piece has modest commercial value.

Geological facts

Geodes commonly begin as gas bubbles in lava and develop layered silica linings over long periods. The dark center could be basaltic material, iron/manganese oxides, or another mineral, but visual evidence is insufficient for a precise identification.

Field identification & locations

Look for a hard, silica-rich rind, waxy chalcedony, and possible sparkling quartz crystals; a steel file should not easily scratch it. Common sources include Brazil, Uruguay, Mexico, and the western United States.