Amethyst
Silicon Dioxide (SiO2) with iron impurities
Rock Type: mineral

Physical Properties
Hardness: 7 (Mohs scale), Color: Purple to deep violet, Luster: Vitreous, Crystal structure: Trigonal (hexagonal prisms), Cleavage: None (conchoidal fracture), Specific gravity: 2.65
Formation & Geological History
Found within geodes in igneous rocks or as veins in hydrothermal deposits. Formed during the cooling of molten rock when gas bubbles trap mineral-rich water, crystallizing over millions of years. Color results from irradiation of iron impurities.
Uses & Applications
Primarily used in jewelry (faceting into gemstones), ornamental sculptures, and as a popular mineral specimen for collectors and home decor.
Geological Facts
The name comes from the Greek word 'amethystos', meaning 'not intoxicated', as it was believed to prevent drunkenness. It is the birthstone for February. Large geodes are commonly found in Brazil and Uruguay.
Field Identification & Locations
Identified by its distinctive purple color and hexagonal prism shape. Often found in basalt cavities. Collectors should look for deep uniform saturation and high clarity in natural specimens.
Identified on: 4/29/2026
Mode: Standard