mineral

Amethyst (Tumbled/Weathered Quartz)

Amethyst (SiO2 with iron impurities)

Hardness: 7 (Mohs scale); Color: Pale to deep purple; Luster: Vitreous/Glassy (sub-vitreous when frosted); Crystal Structure: Hexagonal/Trigonal; Cleavage: None (Conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Pale to deep purple
Luster: Vitreous/Glassy (sub-vitreous when frosted)

Identified March 21, 2026More mineral →

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Physical properties

Formation & geological history

Forms in hydrothermal veins or geodes within volcanic rocks where silica-rich fluids deposit crystals. Its purple color results from irradiation of trivalent iron (Fe3+) within the quartz structure. Most specimens range from 50 to 200 million years old.

Uses & applications

Predominantly used for jewelry, lapidary arts, metaphysical collecting, and ornamental decorative pieces. In industrial contexts, synthetic quartz is used, but natural amethyst is strictly for aesthetics.

Geological facts

Ancient Greeks believed amethyst could prevent intoxication; the name comes from 'amethystos' meaning 'not drunken.' It is the official birthstone of February.

Field identification & locations

Identify by its distinctive purple hue and lack of cleavage. In the field, look for hexagonal crystal points in volcanic outcrops or rounded, frosted pebbles in riverbeds or beaches. Common locations include Brazil, Uruguay, Zambia, and Canada.

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