Carnelian
Quartz var. Carnelian · Semi-Precious Gemstone
Crystal System
Trigonal, microcrystalline massive habit
Mineral Group
Silicates, Tectosilicates
Chemical Formula
SiO2
Formation Process
Hydrothermal and low-temperature deposition in cavities of volcanic rocks
About This Crystal
A polished, tumbled stone displaying a vibrant orange-red to brownish-red color with semi-translucent to opaque areas, a waxy to vitreous luster, and dark inclusions near the base.
Physical Characteristics
Color ranges from orange to reddish-orange; white streak; no cleavage; conchoidal fracture; specific gravity around 2.60 to 2.65; brittle tenacity; inert to weak fluorescence under UV light
Optical Properties
Uniaxial positive, doubly refractive, refractive index of approximately 1.544 to 1.553, no pleochroism
Hardness & Durability
Origin Region
India, Brazil, Madagascar, Uruguay, and the United States
Hardness & Durability
Mohs hardness of 6.5 to 7, good toughness due to microcrystalline structure, stable under normal wear
Care & Maintenance
Clean with warm soapy water and a soft cloth, avoid harsh chemicals and prolonged direct sunlight to prevent fading
Rarity & Value
Common and widely available, affordable pricing, heat treatment of common chalcedony is frequently used to enhance red color
Special Characteristics
Microcrystalline fibrous structure, colored primarily by dispersed iron oxide and hydroxide impurities
Lore & History
Historically used in ancient Rome, Greece, and Egypt for signet rings and talismans, associated with courage, vitality, and motivation, and linked to the sacral chakra