Amethyst
Quartz var. Amethyst · Semi-Precious Gemstone
Crystal System
Trigonal, typically forming prismatic crystals terminating in rhombohedrons, often found as geodes or massive aggregates
Mineral Group
Silicates, specifically Tectosilicates
Chemical Formula
SiO2
Formation Process
Hydrothermal and magmatic processes, precipitating from silica-rich solutions at low to moderate temperatures within gas cavities in volcanic rocks
About This Crystal
A deep purple, rounded cabochon gemstone set in a pendant mounting, exhibiting a vitreous to waxy luster, opaque to translucent transparency, and a smooth polished surface
Physical Characteristics
Purple body color, white streak, conchoidal fracture, lack of distinct cleavage, specific gravity of approximately 2.65, brittle tenacity, and generally non-fluorescent though some specimens show weak blueish fluorescence
Optical Properties
Uniaxial positive optical character, refractive index of 1.544 to 1.553, birefringence of 0.009, doubly refractive, with faint dichroism showing reddish-purple and bluish-purple hues
Hardness & Durability
Origin Region
Brazil, Uruguay, Madagascar, Zambia, and the United States, typically forming in volcanic rock cavities or hydrothermal veins
Hardness & Durability
Mohs hardness of 7, fair to good durability suitable for everyday jewelry with proper care, though vulnerable to harsh impacts due to lack of cleavage and brittle nature
Care & Maintenance
Clean with warm soapy water using a soft brush, avoid ultrasonic cleaners and harsh chemicals, store away from prolonged direct sunlight to prevent color fading
Rarity & Value
Common to moderately rare depending on saturation, value determined by deep color intensity and clarity, price ranging from affordable to moderate for commercial grade cabochons, with heat treatment occasionally used to alter color to yellow citrine
Special Characteristics
Natural color zoning and trace iron impurities irradiated by natural background radiation to produce the characteristic violet hue
Lore & History
Historically associated with royalty, sobriety, and spiritual protection in ancient Greek and Egyptian cultures, widely used in modern crystal healing to represent the third eye and crown chakras for calming and meditative properties