Amethyst
Quartz var. Amethyst · Semi-Precious Gemstone
Crystal System
Trigonal; typically occurs as hexagonal prisms terminated by rhombohedra. This specimen is a polished palm stone.
Mineral Group
Silicates (Tectosilicate subgroup)
Chemical Formula
SiO2 (Silicon Dioxide) with traces of iron (Fe3+) and natural irradiation
Formation Process
Primarily hydrothermal, forming in geodes within volcanic rocks or in hydrothermal veins under relatively low temperatures.
About This Crystal
A deep purple, translucent to semi-opaque polished stone. It shows characteristic color zoning and white feather-like inclusions or 'color bands' typical of natural quartz crystals.
Physical Characteristics
Color: Violet to deep purple; Streak: White; Cleavage: None; Fracture: Conchoidal; Specific Gravity: 2.65; Fluorescence: Generally inert, occasionally weak blue or green.
Optical Properties
Refractive Index: 1.544-1.553; Birefringence: 0.009; Uniaxial (+); Dichroism: Weak to moderate purple/reddish-purple.
Hardness & Durability
Origin Region
Major sources include Brazil (Rio Grande do Sul), Uruguay, Madagascar, Zambia, and Russia (Ural Mountains).
Hardness & Durability
Mohs Hardness: 7; Toughness: Good; Stability: Stable to light but can fade with prolonged exposure to high heat or UV radiation.
Care & Maintenance
Clean with warm soapy water and a soft brush. 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 ('Siberian' deep purple is most prized), clarity, and size. Highly affordable in polished forms.
Special Characteristics
Displays distinct color zoning and can contain 'tiger stripe' inclusions or liquid-filled cavities. It is piezoelectric and pyroelectric.
Lore & History
Historically worn by ancient Greeks to prevent intoxication (from 'amethystos', meaning 'not drunken'). Associated with the Crown Chakra and believed to promote calm and clarity.