gemstone

Polished carnelian agate

Chalcedony (microcrystalline quartz), SiO₂, colored orange-red by iron oxides

AI-generated identification · may be incorrect

Typically Mohs 6.5–7; translucent orange, amber, reddish-brown, or cream with waxy to vitreous luster. Fibrous cryptocrystalline quartz lacks visible cleavage and has conchoidal fracture; the glossy surface appears polished or tumbled.

Identified September 15, 2026More gemstone →

Explore Polished carnelian agate 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 staining producing the warm colors; commonly associated with volcanic rocks, usually formed in Phanerozoic volcanic terrains.

Uses & applications

Used for cabochons, beads, carvings, ornaments, and lapidary specimens; durable enough for jewelry and decorative objects.

Geological facts

Carnelian is an orange-red variety of chalcedony, while agate commonly shows banding or color zoning. Heat treatment can intensify its red-orange color.

Field identification & locations

Identify by its translucent warm color, waxy luster, hardness, and conchoidal fracture; common sources include Brazil, India, Uruguay, Madagascar, and the United States. This specimen may be carnelian-rich agate or polished chalcedony.