Amethyst (Chevron or Banded variety)
Quartz var. Amethyst · Semi-Precious Gemstone
Crystal System
Trigonal; typically prismatic but shown here as a tumbled/polished mass with V-shaped 'chevron' banding
Mineral Group
Silicates (Tectosilicate)
Chemical Formula
SiO2 (Silicon Dioxide) with trace amounts of Iron (Fe3+) and irradiation for color
Formation Process
Hydrothermal; formed from silica-rich solutions in cavities of volcanic rocks at low to moderate temperatures
About This Crystal
A tumbled gemstone featuring alternating bands of purple amethyst and white milky quartz. It has a vitreous luster, is translucent to opaque, and shows distinct color zoning.
Physical Characteristics
Color: Purple and white; Streak: White; Fracture: Conchoidal; Specific Gravity: 2.65; Fluorescence: Usually inert but can show weak green under UV
Optical Properties
Refractive Index: 1.544–1.553; Birefringence: 0.009; Weak pleochroism in purple areas; Uniaxial positive
Hardness & Durability
Origin Region
Brazil, Uruguay, Zambia, and South Africa; found in volcanic geodes and hydrothermal veins
Hardness & Durability
Mohs Hardness: 7; Good toughness; Stable but can fade under prolonged intense sunlight or high heat
Care & Maintenance
Clean with warm soapy water; avoid ultrasonic cleaners if there are many inclusions; store away from direct sunlight to prevent fading
Rarity & Value
Common; value depends on color saturation and pattern clarity; Chevron varieties are affordable and popular for collectors
Special Characteristics
Distinctive V-shaped chevron banding caused by alternating growth layers of amethyst and milky quartz
Lore & History
Ancient Greeks believed it prevented intoxication; Chevron Amethyst is traditionally associated with the Third Eye chakra and inner vision in lore