mineral

Carnelian

Carnelian (a variety of Chalcedony); SiO2 (Silicon Dioxide)

Hardness: 6.5–7 on the Mohs scale. Color: Translucent reddish-brown to orange-red. Luster: Vitreous to waxy. Crystal Structure: Trigonal (cryptocrystalline). Cleavage: None. Specific Gravity: 2.58–2.64.

Hardness: 6
Color: Translucent reddish-brown to orange-red
Luster: Vitreous to waxy

Identified March 29, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the deposition of silica from groundwater into cavities of igneous or sedimentary rocks. The red color is caused by iron oxide impurities. It can be found in volcanic rock gas bubbles (vugs) or as water-worn pebbles in alluvial deposits.

Uses & applications

Predominantly used as a gemstone in jewelry (beads, cabochons), for ornamental carvings, and historical seal stones.

Geological facts

In ancient Egypt, carnelian was believed to assist the deceased in their journey to the afterlife and was often buried with royals. It was also used in Roman signet rings for sealing wax because the wax does not stick to it.

Field identification & locations

Identify in the field by its waxy luster, translucency (hold to light), and conchoidal fracture. Commonly found in India, Brazil, Egypt, and Uruguay. Collectors should look for vibrant evenness of color.

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