Blue Chalcedony
Quartz var. Chalcedony · Semi-Precious Gemstone
Crystal System
Trigonal, microcrystalline cryptocrystalline structure
Mineral Group
Silicates (Tectosilicates)
Chemical Formula
SiO2
Formation Process
Low-temperature hydrothermal deposition and precipitation from silica-rich solutions in rock cavities
About This Crystal
Tumbled stone featuring a soft, pale ice-blue to grayish-blue color. It has a smooth, polished surface with a waxy to vitreous luster, showing subtle translucency and faint banding typical of cryptocrystalline quartz varieties.
Physical Characteristics
Color ranges from pale blue to lavender-blue, white streak, no distinct cleavage (fractures conchoidally), specific gravity around 2.60 to 2.65, brittle tenacity, generally inert under UV light.
Optical Properties
Refractive index ranges from 1.530 to 1.540, doubly refractive with a microcrystalline aggregate structure, uniaxial positive, no significant pleochroism.
Hardness & Durability
Origin Region
Namibia, Madagascar, USA, Turkey, and Brazil in hydrothermal veins and volcanic cavities
Hardness & Durability
Mohs hardness of 6.5 to 7, good durability and toughness due to its microcrystalline interlocking fibrous structure, making it suitable for most types of jewelry.
Care & Maintenance
Easy to care for; can be cleaned using warm soapy water and a soft brush. Avoid harsh chemical cleaners or prolonged exposure to direct, intense sunlight to maintain its color.
Rarity & Value
Common to uncommon depending on the saturation of the blue color. High-grade translucent blue material from specific localities like Namibia can command higher prices, but standard tumbled pieces are very affordable.
Special Characteristics
Cryptocrystalline microfibrous structure (moganite and quartz intergrowths), sometimes exhibiting subtle chatoyancy or banding patterns.
Lore & History
Historically used by ancient civilizations for amulets and carvings. In modern crystal healing, it is traditionally associated with the throat chakra, promoting calm communication, emotional balance, and inner peace.