Amethyst Cluster
Amethyst (Silicon Dioxide), chemical formula: SiO2
Rock Type: mineral

Physical Properties
Hardness: 7 on Mohs scale; Color: Pale lavender to deep violet; Luster: Vitreous; Crystal Structure: Hexagonal (Trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
Formation & Geological History
Formed in hydrothermal veins or as linings in geodes. The purple color comes from irradiation of iron impurities within quartz crystals. Most major commercial deposits are found in basaltic rocks from the Cretaceous period.
Uses & Applications
Primarily used in jewelry (faceting), household decoration, and by mineral collectors for its aesthetic appeal.
Geological Facts
Amethyst is the birthstone for February. The name comes from the Greek 'amethystos', meaning 'not intoxicated', as ancient Greeks believed the stone could prevent drunkenness.
Field Identification & Locations
Identify in the field by its distinct purple hue and six-sided prismatic crystals terminating in pyramids. Commonly found in Brazil, Uruguay, and Zambia. Collectors should look for deep, uniform color and undamaged crystal tips.
Identified on: 4/16/2026
Mode: Standard