mineral

Tumbled orange chalcedony or carnelian

Microcrystalline quartz (SiO₂), likely iron-stained chalcedony

AI-generated identification · may be incorrect

Mohs hardness 6.5–7; translucent pale orange to peach, with a waxy-to-dull luster and no visible crystal faces. It typically has cryptocrystalline quartz structure, conchoidal fracture, and specific gravity around 2.6.

Identified August 14, 2026More mineral →

Explore Tumbled orange chalcedony or carnelian 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 the orange color; commonly Cenozoic to older volcanic-hosted material. The rounded shape indicates tumbling or natural abrasion.

Uses & applications

Used as an ornamental stone, cabochon, bead, and low-cost jewelry material; polished pieces are also popular for collecting and crafts.

Geological facts

Carnelian is the orange-red variety of chalcedony, though pale specimens may be marketed simply as orange chalcedony. Color can intensify with gentle heating because iron oxides are redistributed.

Field identification & locations

Common sources include India, Brazil, Uruguay, Madagascar, and the western United States. Identification is supported by hardness sufficient to scratch glass, lack of cleavage, translucent edges, and a smooth waxy appearance; definitive testing requires microscopy or spectroscopy.