Amethyst

Amethyst (Silicon Dioxide, SiO2)

Rock Type: mineral

Amethyst

Physical Properties

Hardness: 7 on Mohs scale; Color: Purple, violet, or lavender; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: Indistinct/Conchoidal fracture; Specific Gravity: 2.65

Formation & Geological History

Forms in hydrothermal veins or as linings inside volcanic geodes. The purple color is caused by trace amounts of iron irradiation during formation within igneous rock cavities.

Uses & Applications

Widely used for jewelry (faceted gems and beads), ornamental carvings, and decorative mineral specimens for collectors.

Geological Facts

Amethyst was considered a precious stone of equal value to diamonds until large deposits were found in Brazil in the 19th century. Its name comes from the Greek word 'amethystos', meaning 'not intoxicated'.

Field Identification & Locations

Identify by its distinct purple hue and crystal shapes. Found globally, with major deposits in Brazil, Uruguay, and Zambia. Collectors should look for deep uniform color and clarity.

Identified on: 5/13/2026

Mode: Standard