mineral

Tumbled agate (likely moss or dendritic agate)

Microcrystalline quartz, chiefly chalcedony (SiO₂), with iron-oxide and possible manganese inclusions

AI-generated identification · may be incorrect

Hardness 6.5–7 Mohs; brown, amber, gray, and translucent; vitreous to waxy luster; cryptocrystalline quartz with no cleavage and conchoidal fracture. Rounded and polished, it appears naturally banded or inclusion-rich.

Identified August 22, 2026More mineral →

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At a glance

Common name: Tumbled agate (likely moss or dendritic agate)
Scientific name: Microcrystalline quartz, chiefly chalcedony (SiO₂), with iron-oxide and possible manganese inclusions
Category: mineral
Identified: August 22, 2026
Method: Standard

AI Estimated Value

About $3–$15 for a small common tumbled stone; $20–$100+ for unusually attractive patterns, strong translucency, or provenance.

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

Agate forms when silica-rich groundwater fills cavities in volcanic rock, depositing chalcedony and quartz in layers over millions of years, commonly during the Cenozoic or older volcanic episodes.

Uses & applications

Used for cabochons, beads, carvings, bookends, and ornamental objects; valued mainly as an inexpensive collectible gemstone.

Geological facts

The visible pale branching or cloudy patterns may be dendritic inclusions rather than true moss structures; polishing enhances its translucency and color.

Field identification & locations

Identify by its waxy translucence, hardness, conchoidal fracture, and fine banding or mineral inclusions; common sources include Brazil, Uruguay, India, Mexico, Madagascar, and the United States.