mineral

Ametrine

Ametrine (SiO2 - Silicon Dioxide with trace amounts of Iron)

Hardness: 7 (Mohs scale); Color: Dichroic purple (Amethyst) and yellow/orange (Citrine); Luster: Vitreous; Crystal Structure: Trigonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Dichroic purple (Amethyst) and yellow/orange (Citrine)
Luster: Vitreous

Identified March 25, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Dichroic purple (Amethyst) and yellow/orange (Citrine); Luster: Vitreous; Crystal Structure: Trigonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Formation & geological history

Formed in hydrothermal veins through various oxidation states of iron within the quartz crystal lattice. The distinct color zones are caused by a temperature gradient across the crystal during its growth. Most natural specimens come from the Anahi mine in Bolivia.

Uses & applications

Primary use is in jewelry as a faceted gemstone. Collectors value it for its unique bi-color appearance and it is frequently used in high-end artisanal lapidary work.

Geological facts

Legend says the stone was first introduced to Europe in the 1600s as a gift to the Spanish Queen by a conquistador who received the Anahi mine as a dowry. It is a rare naturally occurring variety of quartz because it requires specific temperature conditions to maintain both colors.

Field identification & locations

Identify by its unique dual-color zoning of sharp purple and yellow. In the field, look for hexagonal crystal prisms that exhibit the distinct color split. Natural ametrine is essentially exclusive to Bolivia, while synthetic versions are often produced in laboratories.

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