gemstone

Orange carnelian (possibly treated agate/chalcedony)

Cryptocrystalline quartz, SiO₂; chalcedony variety colored by iron oxides

AI-generated identification · may be incorrect

Mohs hardness 6.5–7; translucent orange to red-orange, with waxy to vitreous luster and no visible crystal faces. It has conchoidal fracture, indistinct cleavage, and specific gravity around 2.58–2.64; the rounded surface suggests polishing or tumbling.

Identified September 19, 2026More gemstone →

Explore Orange carnelian (possibly treated agate/chalcedony) in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Forms when silica-rich groundwater fills cavities and fractures, with iron impurities producing orange-red color; commonly associated with volcanic rocks and generally formed from Cenozoic to older deposits. Strongly uniform color may indicate heat treatment or dyeing.

Uses & applications

Used for beads, cabochons, carvings, ornaments, and inexpensive jewelry; polished pieces are popular among collectors.

Geological facts

Carnelian is a traditional seal-stone and was widely used in ancient Egypt, Greece, Rome, and Mesopotamia. Heating can intensify pale brown chalcedony to vivid orange-red.

Field identification & locations

Identify with its waxy luster, translucency, hardness, and conchoidal fracture; it should scratch glass but not be scratched by a steel knife. Common sources include India, Brazil, Uruguay, Madagascar, and Germany.