mineral

Polished agate or jasper nodule

Microcrystalline quartz, SiO₂, likely chalcedony with iron-oxide and other mineral inclusions

AI-generated identification · may be incorrect

Brown, cream, gray, and translucent bands or patches with a waxy-to-glassy luster; hardness about 6.5–7 Mohs, no cleavage, conchoidal fracture, and microcrystalline quartz structure. The dark areas may be iron/manganese-rich inclusions or matrix.

Identified September 5, 2026More mineral →

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At a glance

Common name: Polished agate or jasper nodule
Scientific name: Microcrystalline quartz, SiO₂, likely chalcedony with iron-oxide and other mineral inclusions
Category: mineral
Identified: September 5, 2026
Method: Standard

AI Estimated Value

Approximately $5–$30 for a common polished specimen; $30–$100+ if unusually large, vividly patterned, or from a desirable locality.

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, depositing chalcedony and quartz in successive layers over millions of years, commonly during the Cenozoic or older volcanic episodes.

Uses & applications

Used as a lapidary stone for cabochons, carvings, beads, and polished display pieces; generally decorative rather than industrial.

Geological facts

The irregular banding and strong polish are typical of agate-group materials, though the specimen could also be jasper or brecciated chalcedony; a photo cannot reliably distinguish them.

Field identification & locations

Common in volcanic terrains worldwide, including Brazil, Uruguay, Mexico, Madagascar, India, and the western United States. Identify by hardness, waxy luster, translucency, and fine banding; avoid scratching unless testing is acceptable.