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Gemstone profile and identification guide

Ametrine

Ametrine is a bicolour quartz variety containing distinct amethyst and citrine colour zones.

7 Mohs Purple, Yellow Silicate (Quartz)
Ametrine

Overview

Ametrine is a bicolour quartz variety containing distinct amethyst and citrine colour zones.

Did you know? Synthetic and treated bicolour quartz can imitate natural ametrine, so origin and growth features matter.

Use this profile as a collector reference and educational guide for quick on-page comparison, then validate with the interactive identification system.

Identification

Name: Ametrine

Scientific classification: Silicate (Quartz)

Hardness: 7 Mohs

Transparency: transparent

Lustre: vitreous

Crystal system: Trigonal

Primary colour: Purple

Secondary colour: Yellow

Colour family: Purples

Quartz constants plus internally zoned purple-yellow colour sectors are diagnostic.

Verification Status

Status: verified-core-fields

Reference priority: GIA, Gem-A, Mindat, International Gem Society

Core identity, locality, and physical-property fields reviewed against standard gemological references.

Values are reported as practical gemological ranges where appropriate.

Physical Properties

Hardness category: hard

Hardness value: 7 Mohs

Chemical composition: Silicon dioxide (SiO2)

Crystal system: Trigonal

Common locations: Bolivia (Anahi mine), Brazil

Learn more: Gem-A gemstone education resources.

Colour Variations

Bicolour quartz combining amethyst purple and citrine yellow sectors in one crystal.

Optical effects: Colour Zoning

Detailed Gemology

Mineral species: Quartz (ametrine variety)

Mineral group: Quartz group

Chemical formula: Silicon dioxide (SiO2)

Mohs hardness: 7

Crystal system: Trigonal

Lustre: vitreous

Transparency: transparent

Streak: White

Cleavage: None

Fracture: Conchoidal

Specific gravity: 2.65

Refractive index: 1.544-1.553

Optical phenomena: Colour zoning

Colour range: Purple and yellow in distinct zones

Common inclusions: Growth zoning, veils, liquid inclusions

Geological environment: Hydrothermal quartz veins

Principal mining regions: Bolivia (Anahi mine), Brazil

Important commercial sources: Most natural commercial ametrine is associated with Bolivia, especially the Anahi area

Historical significance: Commercially popularized from Bolivian production in modern gem markets.

Common treatments: Heating and irradiation can create or modify bicolour appearance.

Synthetic or imitation forms: Synthetic quartz and colour-zoned glass imitations exist.

Common look-alikes: Bi-colour treated quartz, glass

Jewellery uses: Used in faceted jewellery and collector quartz cuts emphasizing colour zoning.

Care recommendations: Durable for regular wear; avoid prolonged high heat and strong light for colour stability.

Cross-check profile data with GIA Gem Encyclopedia and Mindat entry for Ametrine.

Formation

Forms in quartz crystals where differential oxidation and natural heating create purple and yellow sectors.

Origin

Most natural commercial ametrine is associated with Bolivia, especially the Anahi area

Uses

Best for: Used in faceted jewellery and collector quartz cuts emphasizing colour zoning.

Ideal uses: Fantasy cuts and faceting that showcase sharp colour boundaries.

Ametrine FAQ

How can I identify Ametrine?

Compare hardness (7 Mohs), crystal system (Trigonal), colour profile, and lustre (vitreous) with your sample. Then cross-check related gemstones listed above.

What colour range does Ametrine appear in?

Bicolour quartz combining amethyst purple and citrine yellow sectors in one crystal.

Where is Ametrine commonly used?

Fantasy cuts and faceting that showcase sharp colour boundaries.. For maintenance, follow the care guidance in this profile.