mineral

Amethyst quartz cluster

Quartz, SiO₂; purple variety colored mainly by iron impurities and irradiation

AI-generated identification · may be incorrect

Mohs hardness 7; vitreous luster; purple to lilac crystal faces with white translucent quartz matrix. Hexagonal (trigonal) crystal structure, no true cleavage, conchoidal fracture; specific gravity about 2.65.

Identified August 26, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich hydrothermal fluids or volcanic gases deposit quartz in cavities and geodes, commonly alongside iron-bearing minerals. Crystals range from relatively young cavity fillings to specimens formed millions of years ago.

Uses & applications

Used as a gemstone, ornamental mineral, and collector specimen; prized faceted or polished, though this small rough cluster is primarily decorative.

Geological facts

Amethyst’s color can fade with prolonged heating or strong sunlight; yellow heating products are often sold as citrine. The specimen appears to contain pale purple quartz crystals on a light-colored matrix.

Field identification & locations

Identify by purple, glassy quartz crystals, hardness sufficient to scratch ordinary glass, and lack of cleavage; common sources include Brazil, Uruguay, Zambia, and Mexico. Exact locality cannot be determined visually.