mineral

Amethyst and Citrine (Quartz variants)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Purple (Amethyst) and Pale Yellow/Golden (Citrine); Luster: Vitreous; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (Conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Purple (Amethyst) and Pale Yellow/Golden (Citrine)
Luster: Vitreous

Identified May 19, 2026More mineral →

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Physical properties

Formation & geological history

Formed in hydrothermal veins and volcanic geodes when silica-rich fluids crystallize. The purple color in amethyst comes from iron impurities and natural irradiation, while citrine's color comes from different iron states or heat treatment.

Uses & applications

Widely used for jewelry, lapidary art, collection specimens, and metaphysical practices. Historically used for drinking vessels and seals.

Geological facts

Amethyst was once considered a 'Cardinal Gem' alongside diamond and ruby until large deposits were found in Brazil. Citrine is often called the 'Merchant's Stone' for its association with prosperity.

Field identification & locations

Identify in the field by its hardness (scratches glass), lack of cleavage, and characteristic purple or yellow hues. Common locations include Brazil, Uruguay, Africa, and the USA (Arizona/North Carolina).

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