gemstone

Polished carnelian agate

Carnelian, a translucent orange variety of chalcedony (microcrystalline quartz, SiO₂)

AI-generated identification · may be incorrect

Mohs hardness 6.5–7; orange to reddish-brown, waxy to vitreous luster, cryptocrystalline structure, no visible cleavage. The rounded, polished piece shows color zoning typical of agate; the small pale area may be a natural inclusion or surface mark.

Identified October 3, 2026More gemstone →

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Physical properties

Formation & geological history

Forms as silica-rich chalcedony filling cavities in volcanic rocks, with iron compounds producing its color. Such deposits occur in many ages and regions; this image alone cannot determine the specimen’s geological age or source.

Uses & applications

Used for beads, cabochons, carvings, and ornamental objects; historically fashioned into seals and jewelry.

Geological facts

Carnelian is a traditional gemstone and is often heat-treated to deepen its orange-red color.

Field identification & locations

Identify by its translucent orange color, waxy polish, and hardness; common sources include India, Brazil, Uruguay, and Madagascar. A scratch test can damage a finished piece, so inspect under magnification instead.