Amethyst
Quartz var. Amethyst · Semi-Precious Gemstone
Crystal System
Trigonal, with a macrocrystalline habit forming prismatic crystals, though shown here as polished spherical beads cut from massive or geode-derived material.
Mineral Group
Silicates (Tectosilicate subgroup)
Chemical Formula
SiO2
Formation Process
Hydrothermal and magmatic processes, precipitating from silica-rich aqueous solutions within cavities of volcanic rocks (basaltic vesicles) at low to moderate temperatures.
About This Crystal
The specimen is a beaded stretch bracelet consisting of spherical polished gemstones displaying translucent to semi-opaque clarity and a vitreous to waxy luster. The color ranges from pale lilac to deep purple, featuring characteristic chevron zoning, white quartz banding, and cloudy internal inclusions.
Physical Characteristics
Body color varies from light purple to dark violet with white quartz inclusions; streak is white; no true cleavage due to conchoidal fracture; specific gravity is approximately 2.65; brittle tenacity; displays no significant magnetism; exhibits weak or no fluorescence under UV light.
Optical Properties
Singly or doubly refractive with a low birefringence of 0.009; refractive index ranges from 1.544 to 1.553; uniaxial positive optic sign; weak to moderate pleochroism showing reddish-purple and bluish-purple hues from different angles.
Hardness & Durability
Origin Region
Global distribution with major commercial sources including Brazil, Uruguay, Madagascar, Zambia, and the United States (Arizona). Typically forms in volcanic cavities and hydrothermal veins.
Hardness & Durability
Mohs hardness of 7, making it durable enough for everyday jewelry wear such as bracelets and rings. Moderate toughness, vulnerable to sharp impacts due to conchoidal fracture, but chemically stable against most household substances.
Care & Maintenance
Safe to clean with warm soapy water and a soft brush. Avoid ultrasonic cleaners and harsh chemicals or hydrofluoric acid. Prolonged direct exposure to intense sunlight can cause the purple coloration to fade over time.
Rarity & Value
Common to uncommon depending on color saturation and transparency. Value is determined by deep purple saturation, lack of color zoning, and clarity. Widely available and affordable, though heavily saturated natural specimens command higher prices. Heat treatment to yellow citrine is common, though less applicable to lower-grade zoned material.
Special Characteristics
Exhibits prominent chevron zoning and milky white quartz banding (commonly referred to as Chevron Amethyst or Dogtooth Amethyst). Displays standard piezoelectric and pyroelectric properties inherent to quartz varieties.
Lore & History
Historically worn in ancient civilizations like Greece and Rome to prevent intoxication and maintain a clear mind. Widely associated in modern crystal healing traditions with the Third Eye and Crown chakras, symbolizing spiritual growth, calmness, and protection. These are traditional and cultural beliefs rather than scientifically proven claims.