mineral

Amethyst Geode

Amethyst (Silicon Dioxide, SiO2)

Hardness: 7 (Mohs); Color: Pale violet to deep purple; Luster: Vitreous; Crystal Structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 (Mohs)
Color: Pale violet to deep purple
Luster: Vitreous

Identified July 3, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs); Color: Pale violet to deep purple; Luster: Vitreous; Crystal Structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Formation & geological history

Formed in volcanic rocks (basalt) or sedimentary cavities. As lava cools, gas bubbles create voids where silica-rich fluids permeate and crystallize over millions of years, often during the Cretaceous period in South American deposits.

Uses & applications

Used extensively in jewelry as a gemstone, for decorative home decor, and highly valued by mineral collectors for its metaphysical properties and aesthetic appeal.

Geological facts

The purple color is caused by irradiation of iron impurities within the quartz. It was once considered one of the 'Cardinal Gems' along with diamond, ruby, sapphire, and emerald until large deposits were found in Brazil.

Field identification & locations

Identify by its hexagonal crystal points and purple hue within a rocky exterior shell (cathedral style). Most commonly sourced from the Paraná Basin in Brazil and Artigas in Uruguay.