Rock Identifier
Amethyst (Quartz, purple variety — SiO₂) — mineral
mineral

Amethyst

Quartz, purple variety — SiO₂

AI-generated identification · may be incorrect

Typically Mohs hardness 7, vitreous luster, translucent purple color, and hexagonal crystal structure; cleavage is absent, with conchoidal fracture. The specimen appears as rough, partially crystalline amethyst with pale-to-deep purple zoning.

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Physical properties

Typically Mohs hardness 7, vitreous luster, translucent purple color, and hexagonal crystal structure; cleavage is absent, with conchoidal fracture. The specimen appears as rough, partially crystalline amethyst with pale-to-deep purple zoning.

Formation & geological history

Forms mainly in cavities of volcanic rocks when silica-rich hydrothermal fluids crystallize quartz; purple color results from iron impurities and irradiation. Major deposits are geologically diverse, especially in Brazil, Uruguay, Zambia, and Bolivia.

Uses & applications

Used as a gemstone, ornamental stone, mineral specimen, and occasionally in carvings or polished pieces. It is also popular in metaphysical collections, though claimed healing properties are unverified.

Geological facts

Amethyst is the February birthstone and the purple variety of quartz. Heating can turn it yellow-orange, producing citrine or ametrine-like material.

Field identification & locations

Identify it by its purple quartz composition, glassy luster, hardness, and lack of cleavage; glass usually shows bubbles or softer surfaces. Common localities include Brazilian and Uruguayan basalt geodes, often with well-formed crystals.