gemstone
Carnelian
Quartz (Silicon Dioxide, SiO2)
Hardness of 7 on the Mohs scale, color ranges from orange to reddish-orange and brownish-red, vitreous to waxy luster, trigonal crystal system, conchoidal fracture with no true cleavage, specific gravity of 2.65.
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Physical properties
Hardness of 7 on the Mohs scale, color ranges from orange to reddish-orange and brownish-red, vitreous to waxy luster, trigonal crystal system, conchoidal fracture with no true cleavage, specific gravity of 2.65.
Formation & geological history
Formed in low-temperature environments such as groundwater circulation or volcanic cavities, where silica-rich solutions deposit microcrystalline quartz (chalcedony) with iron oxide impurities over millions of years.
Uses & applications
Widely used in making polished beads, carved gemstones, rings, necklaces, and as a popular ornamental and collectible lapidary material.
Geological facts
Carnelian has been prized since ancient times, frequently used in ancient Rome and Egypt for signet rings and amulets due to wax not sticking to its smooth surface.
Field identification & locations
Identified by its waxy luster, orange to reddish-brown translucency, and lack of cleavage; commonly found in river gravels and volcanic rock cavities worldwide, particularly in India, Brazil, and the US.
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