Amethyst (Tumbled Quarz)

Physical Properties

Hardness: 7 Mohs; Color: Purple, violet; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & Geological History

Formed in hydrothermal veins and volcanic geodes when silica-rich water deposits crystals inside cavities. The purple color is caused by natural irradiation and the presence of trace amounts of iron.

Uses & Applications

Primarily used for jewelry, lapidary arts, decorative items, and as a popular specimen for mineral collectors and metaphysical practices.

Geological Facts

The name comes from the Greek word 'amethystos', meaning 'not intoxicated', as Greeks believed the stone could prevent drunkenness. It was once considered one of the five cardinal gemstones until large deposits were found in Brazil.

Field Identification & Locations

Identify by its purple hue and glass-like luster. It is harder than steel and glass. Frequently found in Brazil, Uruguay, and Africa. Tumbled specimens like the one pictured are smooth and often used as 'pocket stones'.

Identified on: 5/5/2026

Mode: Standard