Carnelian
Chalcedony var. Carnelian · Semi-Precious Gemstone
Crystal System
Trigonal symmetry; Cryptocrystalline (microscopic fibrous quartz) habit with no visible crystal faces in this tumbled form
Mineral Group
Silicates (Tectosilicate group, Quartz family)
Chemical Formula
SiO2 (Silicon Dioxide) colored by Hematite (Fe2O3) impurities
Formation Process
Hydrothermal/Sedimentary; forms when silica-rich fluids deposit in cavities of volcanic rocks at low temperatures
About This Crystal
A translucent to semi-opaque tumbled stone with a waxy to vitreous luster. It exhibits a warm reddish-orange hue with slight internal clouding and subtle color zoning typical of chalcedony.
Physical Characteristics
Color: Orange-red; Streak: White; Cleavage: None; Fracture: Conchoidal; Specific Gravity: 2.58–2.64; Fluorescence: Weak to inert under UV light
Optical Properties
Refractive Index: 1.530–1.540; Birefringence: Weak; Pleochroism: None; Optical Character: Uniaxial positive
Hardness & Durability
Origin Region
Primarily India, Brazil, Uruguay, and Madagascar; typically found in volcanic cavities and sedimentary environments
Hardness & Durability
Mohs Hardness: 6.5–7; Toughness: Excellent (no cleavage makes it very durable for jewelry); Stability: High, though extreme heat can deepen color
Care & Maintenance
Clean with warm soapy water and a soft brush; safe for ultrasonic cleaning if no fractures; avoid harsh chemicals and store separately to prevent scratching softer stones
Rarity & Value
Common; Value is determined by color saturation (deep red-orange is prized) and translucency. It is one of the most affordable gemstones and is frequently heat-treated or dyed
Special Characteristics
Often displays subtle banding when held to the light; microscopic inclusions of hematite provide the signature rusty red-orange color
Lore & History
Historically used in Ancient Egypt for amulets and signet rings to symbolize life and protection. In traditional lore, it is associated with the Sacral Chakra and believed to promote courage, motivation, and creativity.