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

Physical Properties
Hardness: 7 on Mohs scale; Color: Purple to deep violet with white banding (common in tumbled stones); Luster: Vitreous/glassy; Crystal Structure: Hexagonal; Cleavage: None; Specific Gravity: 2.65
Formation & Geological History
Forms in hydrothermal veins and cavities (geodes) within igneous rocks. The purple color is caused by irradiation of iron impurities within the quartz lattice.
Uses & Applications
Widely used for jewelry, decorative carvings, spiritual/metaphysical collecting, and as a birthstone for February.
Geological Facts
Amethyst was once considered as valuable as diamonds until large deposits were found in Brazil. Its name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', as it was believed to prevent drunkenness.
Field Identification & Locations
Identify by its characteristic purple color and ability to scratch glass. Tumbled pieces often show distinct 'V' shaped white patterns known as chevron banding. Commonly found in Brazil, Uruguay, and Zambia.
Identified on: 4/23/2026
Mode: Standard