mineral

Tumbled chalcedony (likely carnelian or orange agate)

Microcrystalline quartz, SiO₂; chalcedony variety, possibly Fe-bearing carnelian

AI-generated identification · may be incorrect

Hardness 6.5–7 Mohs; translucent orange-brown to mauve color, waxy-to-dull luster, very fine cryptocrystalline quartz with no visible cleavage and conchoidal fracture. The smooth rounded shape indicates mechanical tumbling and polishing.

Identified August 26, 2026More mineral →

Explore Tumbled chalcedony (likely carnelian or orange agate) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

At a glance

Common name: Tumbled chalcedony (likely carnelian or orange agate)
Scientific name: Microcrystalline quartz, SiO₂; chalcedony variety, possibly Fe-bearing carnelian
Category: mineral
Identified: August 26, 2026
Method: Standard

AI Estimated Value

Approximately $2–$15 for a common tumbled stone; $20–$100+ for unusually translucent, strongly colored, or well-polished material.

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, commonly during the Cenozoic or older volcanic episodes; iron oxides produce orange-red coloration. Exact age and locality cannot be determined from the photograph.

Uses & applications

Used for beads, cabochons, carvings, ornamental objects, and lapidary collections; lower-grade material is inexpensive decorative stone.

Geological facts

Carnelian is orange-red chalcedony, while agate typically shows distinct internal banding; the specimen appears largely unbanded, so chalcedony or carnelian is more likely than agate.

Field identification & locations

Identify by its glassy-to-waxy appearance, translucency, lack of cleavage, hardness, and inability to scratch it with a steel knife easily; common sources include Brazil, India, Uruguay, Madagascar, and the western United States.