mineral

Tumbled carnelian (orange chalcedony)

Carnelian, a microcrystalline quartz variety; SiO₂, commonly colored by dispersed iron oxides

AI-generated identification · may be incorrect

Typically translucent orange to reddish-brown with waxy-to-glassy luster and no visible crystals; quartz hardness is Mohs 7, specific gravity about 2.6, with conchoidal fracture and no cleavage. The smooth rounded shape indicates mechanical tumbling and polishing.

Identified September 17, 2026More mineral →

Explore Tumbled carnelian (orange 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, later incorporating iron and developing orange-red color through oxidation. Deposits occur in volcanic and sedimentary terrains, generally from relatively young to ancient geological settings.

Uses & applications

Used for beads, cabochons, ornaments, and inexpensive jewelry; polished pieces are also collected as lapidary specimens.

Geological facts

Carnelian is a variety of chalcedony, itself a cryptocrystalline form of quartz. More intense red-orange color and translucency generally increase desirability.

Field identification & locations

Identify by its warm orange color, translucency, waxy polish, hardness, and lack of cleavage; common sources include India, Brazil, Uruguay, Madagascar, and Germany. A scratch test should be avoided on polished specimens.