Amethyst
Quartz var. Amethyst · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Trigonal crystal system; typical habit is hexagonal prisms terminated by rhombohedra, though this specimen is polished into a sphere.
Mineral Group
Silicates (Tectosilicate)
Chemical Formula
SiO2 (Silicon Dioxide) with color resulting from trace amounts of iron (Fe3+) and natural irradiation
Formation Process
Forms via hydrothermal activity at low temperatures within gas cavities (vugs) in volcanic rocks or through sedimentary precipitation.
About This Crystal
Polished spherical form with a vitreous luster. The color is a pale lavender-to-greyish purple with visible internal cloudiness, fractures, and white quartz inclusions.
Physical Characteristics
Color: Pale purple; Streak: White; Cleavage: None; Fracture: Conchoidal; Specific Gravity: 2.65; Fluorescence: Usually inert or weak blue.
Optical Properties
Refractive Index: 1.544–1.553; Uniaxial (+); Birefringence: 0.009; Pleochroism: Weak purple to reddish-purple in darker specimens.
Hardness & Durability
Origin Region
Brazil, Uruguay, Madagascar, and Zambia. Often found in volcanic geodes and hydrothermal veins.
Hardness & Durability
Mohs hardness of 7; Good toughness with no cleavage, making it very durable for jewelry and decorative objects.
Care & Maintenance
Clean with warm soapy water and a soft brush. Avoid prolonged exposure to direct sunlight as UV radiation can cause the purple color to fade.
Rarity & Value
Common; Value is determined by color saturation and clarity. Light-colored or included specimens like this sphere are very affordable.
Special Characteristics
Displays internal veining and phantoms; lacks optical phenomena like chatoyancy, but shows distinctive color zoning common in natural amethyst.
Lore & History
Historically used by ancient Greeks to prevent intoxication. Symbolically associated with the Third Eye and Crown chakras, believed to promote clarity and calm.