Amethyst
Quartz var. Amethyst · Semi-Precious Gemstone
Crystal System
Trigonal, with a tumbled and polished pebble habit
Mineral Group
Silicates (Tectosilicates)
Chemical Formula
SiO2
Formation Process
Hydrothermal and magmatic processes, forming in volcanic gas cavities or pegmatites
About This Crystal
A tumbled, polished purple quartz specimen exhibiting translucent to transparent areas with white color zoning and internal fractures
Physical Characteristics
Purple body color, white streak, no cleavage, conchoidal fracture, specific gravity of 2.65, brittle tenacity, and piezoelectric properties
Optical Properties
Uniaxial positive, refractive index of 1.544-1.553, weak birefringence, and faint pleochroism
Hardness & Durability
Origin Region
Global distribution including Brazil, Uruguay, Madagascar, and Zambia
Hardness & Durability
Mohs hardness of 7, fair to good toughness, durable enough for everyday jewelry with proper care
Care & Maintenance
Clean with warm soapy water, avoid prolonged exposure to direct sunlight to prevent fading, store away from harder stones
Rarity & Value
Common, widely available, value determined by color saturation and clarity, inexpensive in tumbled form
Special Characteristics
Piezoelectric properties, color zoning, and natural irradiation-induced color centers
Lore & History
Historically worn to prevent drunkenness and calm the mind, associated with the third eye and crown chakras in modern crystal healing