mineral
Carnelian (Red Chalcedony)
SiO2 (Silicon Dioxide with Iron Oxide inclusions)
Hardness: 6.5 to 7 on Mohs scale. Color: Translucent reddish-orange to deep brownish-red. Luster: Vitreous to waxy. Crystal structure: Trigonal (microcrystalline/cryptocrystalline aggregate). Cleavage: None (conchoidal fracture). Specific gravity: 2.58 to 2.64.
- Hardness
- 6
- Color
- Translucent reddish-orange to deep brownish-red
- Luster
- Vitreous to waxy
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Physical properties
Hardness: 6.5 to 7 on Mohs scale. Color: Translucent reddish-orange to deep brownish-red. Luster: Vitreous to waxy. Crystal structure: Trigonal (microcrystalline/cryptocrystalline aggregate). Cleavage: None (conchoidal fracture). Specific gravity: 2.58 to 2.64.
Formation & geological history
Formed in low-temperature silica-rich environments, typically deposited within cavities and veins of volcanic rocks (basalts and andesites) or sedimentary rocks through hydrothermal activity.
Uses & applications
Widely used as a gemstone in lapidary arts, jewelry (beads, cabochons, rings), ornamental carvings, seals, and as a popular tumbled rock for mineral collectors.
Geological facts
Carnelian has been used in jewelry making for over 4,500 years. Ancient Egyptians called it 'the setting sun' and buried it with mummies for protection in the afterlife, while ancient Romans used it to carve signet rings for sealing wax documents because hot wax does not stick to carnelian.
Field identification & locations
Identified by its distinctive warm orange-to-red color, microcrystalline structure (no visible individual crystals), waxy sheen, and high hardness (scratches glass). Commonly found in Brazil, India, Madagascar, Uruguay, and parts of the United States (Oregon, Washington).
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