mineral

Amethyst-bearing quartz (rough amethyst)

Quartz, silicon dioxide (SiO₂), purple variety colored mainly by iron-related defects

AI-generated identification · may be incorrect

Typically purple with white or gray quartz; vitreous luster, crystalline structure, and no true cleavage, breaking conchoidally. Mohs hardness is 7 and specific gravity about 2.65; the specimen appears rough and partly matrix-coated.

Identified August 20, 2026More mineral →

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At a glance

Common name: Amethyst-bearing quartz (rough amethyst)
Scientific name: Quartz, silicon dioxide (SiO₂), purple variety colored mainly by iron-related defects
Category: mineral
Identified: August 20, 2026
Method: Standard

AI Estimated Value

Approximately $2–$15 for a small rough common specimen; $20–$100+ if strongly colored, well-crystallized, or from a desirable locality.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

Forms when silica-rich hydrothermal fluids fill cavities in volcanic rocks, especially basalt, where quartz crystals grow over millions of years, commonly during the Cenozoic or older volcanic episodes.

Uses & applications

Used as a gemstone, ornamental material, lapidary rough, and popular mineral-collection specimen; lower-grade pieces are commonly tumbled or polished.

Geological facts

Purple intensity depends on trace iron and irradiation and can fade with prolonged heating or strong sunlight. Amethyst is the February birthstone and a widely collected quartz variety.

Field identification & locations

Identify it by purple transparent-to-translucent quartz, glassy luster, hardness sufficient to scratch ordinary glass, and irregular crystal faces; common sources include Brazil, Uruguay, Zambia, and Mexico. The image alone cannot confirm whether it is natural amethyst or another purple mineral.