gemstone
Carnelian
SiO2 (Silicon Dioxide with Iron Oxide impurities)
Hardness: 6.5-7 (Mohs scale), Color: Orange to reddish-brown, Luster: Vitreous to waxy, Crystal Structure: Trigonal (microcrystalline/cryptocrystalline), Translucency: Translucent to opaque
- Hardness
- 6
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Physical properties
Hardness: 6.5-7 (Mohs scale), Color: Orange to reddish-brown, Luster: Vitreous to waxy, Crystal Structure: Trigonal (microcrystalline/cryptocrystalline), Translucency: Translucent to opaque
Formation & geological history
Formed as a microcrystalline variety of quartz through silica-rich water deposition in volcanic rocks or sedimentary environments. Iron oxide impurities provide the red-orange tint. Found in geodes and as nodules.
Uses & applications
Primarily used as a gemstone for jewelry, Intaglio carvings, beads, and metaphysical specimens.
Geological facts
Ancient civilizations such as the Romans and Egyptians used carnelian for signet rings and amulets because it doesn't stick to hot wax. It was highly valued in antiquity as a gem for kings.
Field identification & locations
Identifiable by its warm orange hue and waxy luster. Frequently found in riverbeds or coastal areas in India, Brazil, and Uruguay. Look for a conchoidal (shell-like) fracture pattern when broken.
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