Chalcedony
Quartz var. Chalcedony · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Trigonal, microcrystalline habit forming massive, nodular, or botryoidal masses
Mineral Group
Silicates (Tectosilicates)
Chemical Formula
SiO2
Formation Process
Hydrothermal and low-temperature aqueous deposition filling cavities and fractures in rocks
About This Crystal
An elongated, semi-translucent to opaque nodular specimen exhibiting a smooth to waxy texture, transitioning from a milky white body to warm golden-yellow and orange tones at one end.
Physical Characteristics
Color ranges from white to orange-brown; white streak; no true cleavage; conchoidal to uneven fracture; specific gravity around 2.60 to 2.65; brittle tenacity
Optical Properties
Refractive index of 1.530 to 1.540; doubly refractive with aggregate birefringence; vitreous to waxy luster
Hardness & Durability
Origin Region
Found worldwide including Brazil, India, Madagascar, and the USA; forms in volcanic and sedimentary environments
Hardness & Durability
Mohs hardness of 6.5 to 7; good toughness and durability suitable for various types of jewelry
Care & Maintenance
Clean with warm soapy water using a soft brush; avoid harsh chemicals and prolonged exposure to extreme heat
Rarity & Value
Common and widely available; value depends on color intensity, translucency, and cutting quality, ranging from very affordable to moderate
Special Characteristics
May exhibit subtle translucency, microcrystalline structure, and color zoning from white to honey-yellow
Lore & History
Historically used in ancient seals and carvings; associated with emotional balance, stability, and calming energy in traditional crystal healing practices