Amethyst
Quartz var. Amethyst · Semi-Precious Gemstone
Crystal System
Trigonal, typically forming as prismatic crystals ending in a pyramid, but presented here as a tumbled, smooth pebble.
Mineral Group
Silicates (Tectosilicate subgroup)
Chemical Formula
SiO2
Formation Process
Hydrothermal and magmatic processes, forming in cavities of volcanic rocks (geodes) at low to moderate temperatures from silica-rich solutions containing trace iron.
About This Crystal
A small, tumbled, and polished gemstone displaying a rich purple or violet color concentrated on one end, grading into a clearer or smoky greyish area on the other. It exhibits a smooth, rounded surface with a vitreous to waxy luster and semi-transparent to translucent clarity.
Physical Characteristics
Color ranges from deep purple to pale violet; white streak; no true cleavage; conchoidal fracture; specific gravity around 2.65; brittle tenacity; displays piezoelectric properties.
Optical Properties
Uniaxial positive optical sign with a refractive index of 1.544-1.553, low birefringence of 0.009, and weak dichroism showing reddish-purple and bluish-purple hues.
Hardness & Durability
Origin Region
Global distribution with notable deposits in Brazil, Uruguay, Madagascar, and Zambia; typically found in volcanic vugs and hydrothermal veins.
Hardness & Durability
Mohs hardness of 7, making it durable enough for everyday jewelry wear, though susceptible to scratching softer materials and being scratched by harder ones like topaz or corundum.
Care & Maintenance
Safe to clean with warm soapy water; avoid prolonged exposure to direct sunlight which can cause the purple color to fade; avoid harsh chemical cleaners, ultrasonic cleaners, and sudden extreme temperature changes.
Rarity & Value
Common to moderately rare depending on saturation, clarity, and size; valued based on deep purple color saturation and lack of visible inclusions; typically affordable for small tumbled specimens.
Special Characteristics
Natural color zoning is often visible, showing alternating bands of darker and lighter purple; exhibits piezoelectricity.
Lore & History
Historically used by ancient Greeks and Romans who believed it prevented intoxication (derived from the Greek word amethystos meaning 'not drunken'); associated in modern crystal healing traditions with the third eye and crown chakras to promote calm, clarity, and spiritual growth.