Carnelian
Quartz var. Carnelian · Semi-Precious Gemstone and Decorative Stone
Crystal System
Trigonal, with microcrystalline quartz habit (Chalcedony)
Mineral Group
Silicates (Tectosilicates)
Chemical Formula
SiO2
Formation Process
Hydrothermal and low-temperature sedimentary processes, depositing silica in cavities of volcanic rocks
About This Crystal
A polished heart-shaped gemstone displaying rich brownish-orange to reddish-orange hues with characteristic cloudy color zoning, translucent to semi-translucent transparency, and a vitreous to waxy luster
Physical Characteristics
Orange to reddish-brown body color with a white streak, conchoidal fracture, no distinct cleavage, specific gravity of approximately 2.58 to 2.64, and brittle tenacity
Optical Properties
Uniaxial positive with a refractive index of roughly 1.530 to 1.540, doubly refractive aggregate, and no significant pleochroism
Hardness & Durability
Origin Region
India, Brazil, Madagascar, Uruguay, and the United States; forms in volcanic and sedimentary environments
Hardness & Durability
Mohs hardness of 6.5 to 7, good toughness, and high durability suitable for daily jewelry wear
Care & Maintenance
Clean with warm soapy water using a soft brush, avoid harsh chemicals, prolonged direct sunlight, and sudden extreme temperature changes
Rarity & Value
Common to uncommon depending on color saturation and translucency, generally affordable with value based on even coloration and lack of fractures; heat treatment is occasionally used to enhance color
Special Characteristics
Microcrystalline structure with cloudy or striped internal distribution of iron oxide impurities causing the characteristic orange color
Lore & History
Historically used by ancient civilizations including the Romans, Egyptians, and Greeks for signet rings and amulets; traditionally associated with courage, vitality, motivation, and the sacral chakra in modern crystal healing practices