mineral

Amethyst-bearing quartz

Quartz, SiO₂; purple coloration from trace iron and irradiation

AI-generated identification · may be incorrect

Typically Mohs hardness 7, vitreous luster, conchoidal fracture, and hexagonal crystal structure; purple with white to gray quartz matrix. The specimen appears rough and partly druzy or crystalline, though the image limits exact identification.

Identified September 7, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids fill cavities in volcanic rocks, especially basaltic geodes; many deposits formed during the Mesozoic or younger. Common sources include Brazil, Uruguay, Zambia, and Bolivia.

Uses & applications

Used as a gemstone, ornamental stone, healing/collection specimen, and source material for polished geodes and cabochons; not generally used as construction aggregate in this form.

Geological facts

Amethyst is the purple variety of quartz; its color can fade with prolonged heat or strong sunlight. Color intensity and crystal transparency strongly affect desirability.

Field identification & locations

Identify by purple quartz crystals, glassy luster, hardness sufficient to scratch ordinary glass, and lack of obvious cleavage. Commonly found in geodes and volcanic cavities; avoid confusing it with purple fluorite, which is softer and cleaves readily.