mineral

Amethyst and Citrine (Ametrine Mix)

Silicon Dioxide (SiO2) with Fe3+ impurities

Hardness: 7 (Mohs scale); Color: Purple (amethyst) and yellow/gold (citrine); Luster: Vitreous (glassy); Crystal structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65.

Hardness: 7 (Mohs scale)
Color: Purple (amethyst) and yellow/gold (citrine)
Luster: Vitreous (glassy)

Identified March 23, 2026More mineral →

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Physical properties

Formation & geological history

Formed in hydrothermal veins or geodes. The purple comes from iron irradiation, while the yellow comes from iron in different oxidation states, often as a result of temperature gradients during formation. Notable for spanning millions of years in volcanic basalt cavities.

Uses & applications

Primarily used in jewelry for beads, cabochons, and faceted gemstones. It is also highly valued in the metaphysical and gemstone collecting communities.

Geological facts

Natural citrine and amethyst occurring together in the same crystal is called 'Ametrine'. Most commercial citrine beads are actually heat-treated amethyst. Ancient Greeks believed amethyst prevented intoxication.

Field identification & locations

Identify by the signature purple and yellow hues and the ability to scratch glass. Found commonly in Brazil, Uruguay, and Bolivia (the world's only commercial source of natural ametrine). Check for color zoning which is a sign of natural origin.

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