Amethyst
Quartz var. Amethyst · Semi-Precious Gemstone
Crystal System
Trigonal, typically forming prismatic crystals terminating in pyramids, but this specimen is tumbled/polished into a smooth pebble shape.
Mineral Group
Silicates (Tectosilicates)
Chemical Formula
SiO2
Formation Process
Hydrothermal and magmatic processes, precipitating from silica-rich solutions within gas cavities in basaltic lavas at low to moderate temperatures.
About This Crystal
A polished, tumbled stone showing distinctive Chevron patterns alternating between deep purple and milky white quartz bands. Translucent to semi-opaque with a vitreous to waxy luster.
Physical Characteristics
Color ranges from deep violet to pale lavender with white banding. Streak is white. Cleavage is absent, fracture is conchoidal. Specific gravity is approximately 2.65. Brittle tenacity.
Optical Properties
Singly or doubly refractive with a low birefringence of 0.009. Refractive index is 1.544 to 1.553. Weak pleochroism showing reddish-purple and bluish-purple shades.
Hardness & Durability
Origin Region
Found globally with notable sources in Brazil, Uruguay, Madagascar, and Zambia. Typically forms in volcanic rock cavities or hydrothermal veins.
Hardness & Durability
Mohs hardness of 7. Good durability, suitable for everyday jewelry wear, though care should be taken to avoid sharp impacts due to brittleness.
Care & Maintenance
Clean with warm, soapy water and a soft brush. Avoid ultrasonic cleaners and harsh chemicals. Prolonged exposure to direct sunlight can cause the purple color to fade.
Rarity & Value
Common to uncommon depending on clarity and color saturation. Inexpensive for tumbled stones, ranging from a few dollars to tens of dollars.
Special Characteristics
Displays distinct chevron banding (V-shaped or zigzag patterns) caused by alternating growth phases of amethyst and white quartz.
Lore & History
Historically used by ancient Greeks and Romans as a talisman against drunkenness and to keep the wearer clear-headed. Associated with the Third Eye and Crown chakras in modern crystal healing, symbolizing peace, clarity, and spiritual growth.