gemstone

Carnelian Agate

Silicon Dioxide (Chalcedony variety), SiO2

Hardness of 6.5 to 7 on the Mohs scale; color ranges from yellowish-orange to deep brownish-red; waxy to vitreous luster; cryptocrystalline structure (microscopic quartz crystals); conchoidal fracture with no true cleavage; specific gravity of 2.58 to 2.64.

Identified July 29, 2026More gemstone →

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Physical properties

Formation & geological history

Formed in the cavities of volcanic rocks or ancient lavas through the deposition of silica from groundwater solutions, often over millions of years.

Uses & applications

Widely used in jewelry-making (rings, beads, pendants), carved into cameos, and collected as a decorative gemstone.

Geological facts

Carnelian has been prized since ancient times, notably in Ancient Egypt where it was worn by builders to give them courage and by nobility as a protective amulet.

Field identification & locations

Easily identified by its translucent reddish-orange color, waxy luster, and smooth tumbled feel; commonly sourced from Brazil, India, Madagascar, and the USA.

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