Carnelian Agate with Quartz Geode Center
Quartz var. Chalcedony and Carnelian · Semi-Precious Gemstone and Decorative Stone
Crystal System
Trigonal, microcrystalline and macrocrystalline habit forming banded nodular formations and quartz crystal linings
Mineral Group
Silicates
Chemical Formula
SiO2
Formation Process
Hydrothermal and low-temperature sedimentary deposition where silica-rich groundwater fills cavities in volcanic rocks, depositing microscopic quartz crystals in concentric layers over long periods
About This Crystal
A polished teardrop-shaped cabochon featuring vibrant reddish-orange carnelian banding transitioning into crisp white chalcedony lines, bordered by a central pocket of translucent crystalline quartz with a sparkling druzy appearance
Physical Characteristics
Vibrant reddish-orange and white body color, white streak, no cleavage, conchoidal to uneven fracture, specific gravity of approximately 2.65, brittle tenacity, vitreous to waxy luster
Optical Properties
Singly refractive for the microcrystalline chalcedony portions and doubly refractive uniaxial positive for the crystalline quartz center, vitreous luster, translucent to opaque
Hardness & Durability
Origin Region
Brazil, India, Madagascar, and the United States, typically found in volcanic and metamorphic rock cavities
Hardness & Durability
Mohs hardness of 6.5 to 7, offering good toughness and wearability suitable for rings, pendants, and other jewelry items
Care & Maintenance
Clean with warm soapy water and a soft brush, avoid harsh chemicals or prolonged exposure to extreme heat and direct sunlight to prevent potential color fading
Rarity & Value
Common to uncommon depending on the vividness of the red color and the aesthetic contrast with the quartz center, generally affordable and widely available
Special Characteristics
Features a combination of banded chalcedony fortification patterns and an open quartz geode center, showcasing both cryptocrystalline and macrocrystalline quartz growth phases
Lore & History
Historically used by ancient civilizations like the Egyptians and Romans for signet rings, talismans, and royal jewelry; traditionally associated with vitality, motivation, and courage in modern crystal healing practices, though these are cultural beliefs and not scientifically proven