Amethyst
Quartz var. Amethyst · Semi-Precious Gemstone
Crystal System
Trigonal; typically hexangular prismatic crystals in nature, though these specimens are tumbled/polished
Mineral Group
Silicates (Tectosilicate)
Chemical Formula
SiO2 (Silicon Dioxide) with traces of Iron (Fe3+)
Formation Process
Found in hydrothermal environments where silica-rich fluids cool in cavities (geodes) of igneous rocks, specifically basalt
About This Crystal
Transparent to translucent purple quartz. These tumbled stones show vitreous luster, characteristic purple color zoning, and white quartz inclusions (chevron patterns)
Physical Characteristics
Color: Pale lilac to deep purple; Streak: White; Fracture: Conchoidal; Specific Gravity: 2.65; Fluorescence: Usually inert or faint blue
Optical Properties
Uniaxial positive; Refractive Index: 1.544–1.553; Birefringence: 0.009; Weak pleochroism in purple/red-purple shades
Hardness & Durability
Origin Region
Brazil, Uruguay, Zambia, Madagascar, and Russia; typically found in volcanic geodes or hydrothermal veins
Hardness & Durability
Mohs hardness: 7; Good toughness; Stable, though color can fade under prolonged intense UV exposure
Care & Maintenance
Wash with warm soapy water; Avoid ultrasonic cleaners if inclusions are present; Keep away from prolonged direct sunlight to prevent fading
Rarity & Value
Common; Value is determined by color depth, clarity, and size. Deep 'Siberian' purple with red/blue flashes is most valuable
Special Characteristics
Typical color-zoning where purple is concentrated at crystal tips; these specimens show white quartz 'phantom' or chevron banding
Lore & History
Ancient Greeks believed it prevented intoxication. Symbolizes sobriety, peace, and spiritual protection; traditionally associated with the Crown Chakra.