Amethyst (Geode Fragment)

Physical Properties

Hardness: 7 on Mohs scale. Color: Pale violet to deep purple. Luster: Vitreous/Glassy. Crystal Structure: Hexagonal (trigonal). Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Formation & Geological History

Formed in igneous or metamorphic environments when silica-rich fluids fill cavities (vugs) created by gas bubbles in lava. The purple color comes from irradiation of trivalent iron (Fe3+) in the quartz structure. Usually dated to the era of volcanic activity in their locality (e.g., Cretaceous in Brazil/Uruguay).

Uses & Applications

Extensively used in jewelry (faceting, cabochons), ornamental decoration, spiritual/metaphysical collecting, and as a semi-precious gemstone.

Geological Facts

Amethyst was considered one of the Cardinal Gems until large deposits were found in Brazil. The name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', as it was believed to protect the wearer from drunkenness.

Field Identification & Locations

Identify by its purple hue and hexagonal crystal habits within a geode shell. Commonly found in Brazil, Uruguay, South Korea, and Ontario, Canada. Collectors look for deep color ('Siberian' quality) and crystal clarity.

Identified on: 4/15/2026

Mode: Standard