Rock Identifier
Tumbled orange chalcedony or carnelian (Microcrystalline quartz (SiO₂), likely iron-bearing chalcedony) — gemstone
gemstone

Tumbled orange chalcedony or carnelian

Microcrystalline quartz (SiO₂), likely iron-bearing chalcedony

AI-generated identification · may be incorrect

Hardness 6.5–7 Mohs; orange-yellow, translucent to opaque, with a smooth vitreous-to-waxy luster and no visible cleavage. Its rounded, polished form is consistent with a tumbled gemstone; exact identification is uncertain from the image alone.

Identified More gemstone
Explore Tumbled orange chalcedony or carnelian in the encyclopedia →

Identify your own rocks.

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

Physical properties

Hardness 6.5–7 Mohs; orange-yellow, translucent to opaque, with a smooth vitreous-to-waxy luster and no visible cleavage. Its rounded, polished form is consistent with a tumbled gemstone; exact identification is uncertain from the image alone.

Formation & geological history

Forms when silica-rich groundwater fills cavities or fractures, with iron oxides producing orange to red coloration; deposits range from ancient volcanic-hosted veins to younger sedimentary environments.

Uses & applications

Used for beads, cabochons, carvings, and ornamental objects; common tumbled pieces typically have modest collector value.

Geological facts

Carnelian is the red-orange variety of chalcedony, while paler orange material may be called orange chalcedony or sard. Color can sometimes be enhanced by heating or dyeing.

Field identification & locations

Identify by its waxy luster, lack of cleavage, translucency, and hardness sufficient to scratch glass; common sources include India, Brazil, Uruguay, Madagascar, and Namibia. A gemological test or specific-gravity measurement is needed to distinguish it from dyed agate, glass, or orange calcite.