mineral
Carnelian
Carnelian (Cryptocrystalline Quartz, SiO2)
Hardness: 6.5-7 on Mohs scale; Color: Red-orange, brownish-red, amber; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal; Cleavage: None; Specific gravity: 2.58-2.64
- Hardness
- 6
- Color
- Red-orange, brownish-red, amber
- Luster
- Vitreous to waxy
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Physical properties
Hardness: 6.5-7 on Mohs scale; Color: Red-orange, brownish-red, amber; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal; Cleavage: None; Specific gravity: 2.58-2.64
Formation & geological history
Forms through the deposition of silica from groundwater into cavities of igneous rocks such as basalt and rhyolite. It is often found in sedimentary environments where volcanic rock has weathered away.
Uses & applications
Primarily used as a gemstone for jewelry (cabochons, beads), decorative carvings, and as a semi-precious stone for mineral collectors. Historically used for signet rings and seals.
Geological facts
Carnelian was highly prized by the ancient Egyptians as the 'setting sun' and was mentioned in the Bible as one of the stones on the Breastplate of Aaron. Its reddish color is due to impurities of iron oxide.
Field identification & locations
Identified by its waxy luster, translucency, and warm orange-red hue. Commonly found in Brazil, India, Uruguay, and Madagascar. Collectors should look for even color distribution and lack of synthetic dyes.
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