gemstone

Polished carnelian (red-orange chalcedony)

Carnelian, a cryptocrystalline variety of quartz (SiO₂), commonly colored by iron oxides

AI-generated identification · may be incorrect

Mohs hardness 6.5–7; translucent red, orange, and yellow zones with a waxy-to-glassy luster and no visible cleavage. It has a trigonal quartz structure and specific gravity around 2.6.

Identified September 12, 2026More gemstone →

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Physical properties

Mohs hardness 6.5–7; translucent red, orange, and yellow zones with a waxy-to-glassy luster and no visible cleavage. It has a trigonal quartz structure and specific gravity around 2.6.

Formation & geological history

Forms when silica-rich groundwater fills cavities and fractures, with iron producing the warm colors; specimens may be millions to hundreds of millions of years old. The polished, possibly carved piece is consistent with lapidary material rather than an intact natural crystal.

Uses & applications

Used for cabochons, beads, carvings, seals, and ornamental objects; durable jewelry material with modest collector value.

Geological facts

Carnelian is a variety of chalcedony closely related to sard, with color determined largely by iron oxidation and heat treatment.

Field identification & locations

Common sources include India, Brazil, Uruguay, Madagascar, and Germany. Identify by hardness, waxy luster, translucency, and lack of cleavage; glass imitations may show bubbles or scratch more easily.