Amethyst (Chevron Amethyst)
Quartz var. Amethyst · Semi-Precious Gemstone
Crystal System
Trigonal, typically forming prismatic crystals ending in a pyramid, though this specimen is a tumbled, massive pebble.
Mineral Group
Silicates, specifically Tectosilicates
Chemical Formula
SiO2
Formation Process
Hydrothermal and magmatic processes, precipitating from silica-rich solutions within gas cavities in basaltic rocks at low to moderate temperatures.
About This Crystal
A tumbled, polished smooth pebble featuring characteristic chevron (V-shaped) banding of deep purple amethyst intergrown with white milky quartz, exhibiting a vitreous luster on its polished surface and translucent to opaque transparency.
Physical Characteristics
Color ranges from deep purple to violet with white quartz zones; streak is white; no true cleavage; conchoidal fracture; specific gravity is approximately 2.65; brittle tenacity; exhibits piezoelectric and pyroelectric properties.
Optical Properties
Singly and doubly refractive with an optic axis, uniaxial positive; refractive index of 1.544 to 1.553; birefringence of 0.009; weak pleochroism showing reddish-purple and bluish-purple shades.
Hardness & Durability
Origin Region
Brazil, Uruguay, Madagascar, Zambia, and the United States; typically forms in volcanic cavities or hydrothermal veins.
Hardness & Durability
Mohs hardness of 7, making it durable and suitable for general jewelry use; good toughness though lacks cleavage which helps prevent easy splitting.
Care & Maintenance
Clean with warm, soapy water and a soft brush; avoid harsh chemicals, ultrasonic cleaners, and prolonged exposure to direct sunlight which can cause the purple color to fade.
Rarity & Value
Common; widely available and affordable, with value determined by the intensity of the purple color and the crispness of the chevron patterning.
Special Characteristics
Displays distinct chevron or zigzag color zoning resulting from alternating growth phases of amethyst and white quartz within the original crystal matrix.
Lore & History
Historically used as a gemstone by ancient Egyptians, Greeks, and Romans who associated it with sobriety and protection; in modern crystal healing, it is traditionally linked to the third eye and crown chakras for spiritual growth, clarity, and inner peace.