Amethyst

Physical Properties

Hardness: 7 on Mohs scale; Color: purple to violet; Luster: vitreous (glassy); Crystal structure: hexagonal/trigonal; Cleavage: none (conchoidal fracture); Specific gravity: 2.65.

Formation & Geological History

Formed in hydrothermal veins or as druzy linings in volcanic rock cavities (geodes). The purple color is caused by natural irradiation of trace iron impurities.

Uses & Applications

Primarily used as a gemstone in jewelry (rings, necklaces), high-end interior decoration, and as a popular metaphysical or collector's specimen.

Geological Facts

Amethyst was once considered one of the 'Cardinal gems' and was more valuable than diamonds until large deposits were discovered in Brazil in the 1700s.

Field Identification & Locations

Identify in the field by its distinct purple hue and prismatic crystals that lack cleavage. Common in Brazil, Uruguay, and Arizona.

Identified on: 5/15/2026

Mode: Standard