Amethyst
Quartz var. Amethyst · Semi-Precious Gemstone and Mineral Specimen
Crystal System
Trigonal, with a macrocrystalline prismatic habit often found as geode linings or massive chunks
Mineral Group
Silicates, specifically Tectosilicates
Chemical Formula
SiO2
Formation Process
Hydrothermal and magmatic processes, precipitating from silica-rich solutions inside cavities of volcanic rocks at low to moderate temperatures
About This Crystal
A deep purple, translucent to transparent crystalline mineral specimen with a vitreous luster, displaying typical uneven fractures and subtle color zoning characteristic of natural quartz
Physical Characteristics
Purple body color with a white streak, lack of true cleavage with a distinct conchoidal fracture, specific gravity around 2.65, brittle tenacity, and typically inert under UV light though some localities show weak yellow or green fluorescence
Optical Properties
Uniaxial positive optical character with a refractive index of 1.544-1.553, low birefringence of 0.009, and 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 cavities and hydrothermal veins
Hardness & Durability
Mohs hardness of 7, making it durable for daily jewelry wear with good toughness, though it lacks cleavage and can fracture under severe impact
Care & Maintenance
Can be cleaned safely with warm soapy water and a soft brush; avoid harsh ultrasonic cleaners, sudden thermal shocks, and prolonged direct sunlight which can cause the purple color to fade
Rarity & Value
Common to moderately rare depending on color saturation and clarity; high-grade deep purple stones from Siberia or Uruguay command higher prices, while typical raw specimens are affordable
Special Characteristics
Displays color zoning, natural phantom inclusions, and piezoelectric properties capable of generating an electrical charge under mechanical stress
Lore & History
Historically revered by ancient Greeks and Romans as a protective amulet against drunkenness and negative energies, highly associated with the Third Eye and Crown chakras in modern crystal healing traditions