gemstone

Tumbled carnelian (orange-brown chalcedony)

Chalcedony, microcrystalline quartz (SiO₂); carnelian is its iron-colored variety

AI-generated identification · may be incorrect

Mohs hardness 6.5–7; translucent to opaque orange-brown with a vitreous to waxy luster and no visible crystal faces. The image shows a smooth, polished/tumbled piece; its precise variety cannot be confirmed visually.

Identified October 14, 2026More gemstone →

Explore Tumbled carnelian (orange-brown chalcedony) in the encyclopedia →

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Physical properties

Formation & geological history

Forms as silica-rich fluids fill cavities and veins in volcanic rocks; iron compounds produce the warm coloration. Chalcedony occurs in rocks of many ages and geological settings.

Uses & applications

Used for beads, cabochons, carvings, and decorative objects; historically valued for seals and jewelry.

Geological facts

Carnelian’s color comes chiefly from iron-bearing impurities, and heating can intensify its reddish-orange tones.

Field identification & locations

Look for translucent orange-to-brown color and a waxy appearance; common sources include India, Brazil, Uruguay, and Madagascar. This small polished specimen would typically sell for about $2–$15, depending on quality and provenance.