gemstone

Polished carnelian agate

Chalcedony, microcrystalline quartz (SiO₂), iron-oxide colored

AI-generated identification · may be incorrect

A polished, rounded orange-brown piece with a pale cream rim and waxy luster. Quartz hardness is 6.5–7 Mohs; its crystals are microscopic, with no visible cleavage and a specific gravity near 2.6. The image alone cannot confirm whether it is natural agate or a carved/chipped piece.

Identified September 23, 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

Chalcedony forms when silica-rich fluids fill cavities and fractures in volcanic rocks; iron impurities produce carnelian’s warm color. Its geological age depends on the host deposit, commonly millions of years.

Uses & applications

Used for beads, cabochons, carvings, and decorative objects; agate is also used in precision components and abrasives.

Geological facts

Carnelian is an orange-to-red variety of chalcedony, and the pale banding suggests agate. The visible shape may be a small carving or fragment rather than an unmodified stone.

Field identification & locations

Check for fine banding, a glassy-to-waxy surface, and hardness sufficient to scratch glass; common sources include India, Brazil, Uruguay, and Madagascar. A photo cannot establish provenance or treatment.