Amethyst
Quartz var. Amethyst · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Trigonal crystal system; displays a massive or crystalline habit, often forming six-sided prisms ending in pyramids.
Mineral Group
Silicates (Tectosilicate subgroup)
Chemical Formula
SiO2 (Silicon Dioxide) with trace amounts of Iron (Fe3+)
Formation Process
Hydrothermal and Igneous; forms when silica-rich fluids crystallize in the cavities of volcanic rock at relatively low temperatures.
About This Crystal
A translucent to transparent violet variety of quartz. This specimen shows a light lavender hue with cloudy white zoning, a vitreous luster, and an irregular, broken surface texture.
Physical Characteristics
Color: Lavender to deep purple; Streak: White; Fracture: Conchoidal; Specific Gravity: 2.65; Fluorescence: Generally inert, but may show weak blue/green under UV.
Optical Properties
Refractive Index: 1.544–1.553; Birefringence: +0.009; Doubly refractive (uniaxial); Weak dichroism visible in darker specimens.
Hardness & Durability
Origin Region
Commonly sourced from Brazil, Uruguay, Madagascar, and Zambia; forms in volcanic cavities (geodes) or hydrothermal veins.
Hardness & Durability
Mohs Hardness: 7; Toughness: Fair to good; durable enough for daily jewelry wear but susceptible to chipping if struck hard.
Care & Maintenance
Wash with warm soapy water; avoid ultrasonic or steam cleaners if there are many inclusions. Store away from direct sunlight to prevent color fading.
Rarity & Value
Common; Value is determined by color saturation (deep purple being most valuable), clarity, and lack of visible zoning. Low price range per carat.
Special Characteristics
Color-zoning (uneven distribution of purple), internal fractures, and potential for bi-colored 'Ametrine' if Citrine is present.
Lore & History
Ancient Greeks believed it prevented intoxication (from 'amethystos', not drunk). Traditionally associated with the Crown Chakra and used to promote calm and sobriety.