gemstone

Polished carnelian chalcedony

Carnelian, a red-orange variety of microcrystalline quartz (SiO₂)

AI-generated identification · may be incorrect

Hardness 6.5–7 Mohs; translucent orange-red to reddish brown, usually waxy to vitreous luster, cryptocrystalline structure, with no visible cleavage and conchoidal fracture. The image appears to show a polished or carved piece, possibly combined with paler chalcedony.

Identified September 13, 2026More gemstone →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater deposits chalcedony in cavities and fractures, with iron impurities producing the color; commonly associated with volcanic rocks and ancient sedimentary environments. Deposits occur worldwide and range from Precambrian to Cenozoic age.

Uses & applications

Used for beads, cabochons, carvings, seals, and ornamental objects; durable but less valuable than transparent quartz gemstones.

Geological facts

Color may intensify with heating or dyeing; natural banding and uneven coloration help distinguish it from glass or dyed material.

Field identification & locations

Identify by its fine texture, waxy luster, hardness, and conchoidal fracture; common sources include India, Brazil, Uruguay, Madagascar, and Germany. A scratch test should be avoided on finished pieces.