Carnelian
Chalcedony var. Carnelian · Semi-Precious Gemstone
Crystal System
Trigonal, microcrystalline quartz with massive or nodular habit, polished into a sphere
Mineral Group
Silicates
Chemical Formula
SiO2
Formation Process
Hydrothermal and sedimentary low-temperature deposition, precipitating from silica-rich groundwater within cavities of volcanic rocks
About This Crystal
A polished spherical gemstone of deep reddish-orange to brownish-red carnelian, featuring a translucent to semi-translucent body with a vitreous to waxy luster. It showcases a prominent, irregular matrix inclusion of white and brown chalcedony/quartz on its surface, displaying natural banding and internal cloudiness.
Physical Characteristics
Orange to reddish-brown body color with a white streak, conchoidal fracture, lack of distinct cleavage, specific gravity of approximately 2.58 to 2.64, and brittle tenacity with no significant magnetism.
Optical Properties
Uniaxial positive optical character with a refractive index around 1.530 to 1.540, double refraction, and no notable pleochroism due to its microcrystalline structure.
Hardness & Durability
Origin Region
Brazil, India, Madagascar, and Uruguay, typically forming in volcanic and sedimentary cavities
Hardness & Durability
Mohs hardness of 6.5 to 7, offering good toughness and making it durable for general jewelry use and handling.
Care & Maintenance
Clean with warm soapy water and a soft brush; avoid harsh chemicals, prolonged direct sunlight to prevent fading, and ultrasonic cleaners if fractures are present.
Rarity & Value
Common to uncommon depending on color saturation and translucency, with value increasing for intensely saturated, uniform red stones without heavy matrix inclusions; treated materials via heat are common.
Special Characteristics
Features a natural contrasting vug or matrix inclusion revealing raw chalcedony layers on the polished sphere surface.
Lore & History
Historically used in ancient Rome, Egypt, and Greece for signet rings and amulets, carnelian is traditionally associated with courage, vitality, motivation, and the sacral chakra in modern crystal healing.