gemstone

Carnelian

Silicon Dioxide, variety of chalcedony (SiO2)

Hardness of 6.5 to 7 on the Mohs scale, color ranges from orange to reddish-orange and brownish-red, vitreous to waxy luster, microcrystalline (cryptocrystalline) crystal structure, conchoidal fracture with no cleavage, specific gravity of 2.58 to 2.64.

Identified August 2, 2026More gemstone →

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Physical properties

Formation & geological history

Formed in low-temperature hydrothermal environments, volcanic cavities, and sedimentary rock settings where silica-rich groundwater deposits microcrystalline quartz over millions of years.

Uses & applications

Widely used in jewelry such as rings, necklaces, and beads, as well as for carved cameos, intaglios, and decorative ornamental items due to its durability and rich color.

Geological facts

Carnelian has a rich history dating back to ancient times; it was heavily favored by the ancient Egyptians for amulets and in the construction of royal jewelry, and was often used as a signet ring stone to seal wax documents.

Field identification & locations

Identified by its translucent orange-to-red coloration and waxy luster; commonly sourced from Brazil, India, Madagascar, and the United States, popular among collectors of polished gemstones.

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ZrO2 (Cubic Zirconia) or C (Diamond)

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Silicon Dioxide (SiO2) with Hematite inclusions

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Black Opal Ring (Carved Opal)

Hydrated Silicon Dioxide (SiO2·nH2O)

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