mineral

Raw amethyst (purple quartz)

Amethyst, violet variety of quartz (SiO₂)

AI-generated identification · may be incorrect

Typically Mohs hardness 7, vitreous luster, purple coloration from iron and irradiation, and a trigonal crystal structure; quartz has indistinct cleavage and conchoidal fracture. The specimen appears rough, translucent purple, and may be fractured or partially weathered.

Identified August 30, 2026More mineral →

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Physical properties

Formation & geological history

Forms mainly in cavities and veins of volcanic rocks when silica-rich groundwater deposits quartz, often over geodes; the host rocks are commonly Mesozoic to Cenozoic volcanic formations. Purple color develops through iron-related defects and natural radiation.

Uses & applications

Used for cabochons, beads, carvings, geodes, mineral specimens, and ornamental objects; fine transparent crystals are used in jewelry, while lower-grade material has modest decorative value.

Geological facts

Amethyst can fade with prolonged heating or strong sunlight, and its color commonly varies from pale lilac to deep violet. It is the birthstone for February.

Field identification & locations

Identify it by its purple color, glassy luster, hardness, and lack of a powdery or flaky texture; genuine quartz will scratch glass but not be scratched easily by a steel knife. Major sources include Brazil, Uruguay, Zambia, and Mexico.