mineral

Amethyst

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

AI-generated identification · may be incorrect

Typically purple, vitreous/glassy luster, translucent to transparent, conchoidal fracture, and no cleavage; Mohs hardness 7, trigonal crystal structure, specific gravity about 2.65. The specimen appears to be a rough, fractured amethyst piece, possibly cut or broken from a larger crystal.

Identified September 13, 2026More mineral →

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At a glance

Common name: Amethyst
Scientific name: Quartz, purple variety — silicon dioxide (SiO₂), colored mainly by iron-related defects
Category: mineral
Identified: September 13, 2026
Method: Standard

AI Estimated Value

Approximately $2–$20 for a small rough fragment; $20–$100+ for attractive display-quality material, with exceptional crystals or jewelry worth considerably more.

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 iron-bearing silica-rich fluids fill cavities in volcanic rocks, especially basaltic geodes, where quartz crystals grow slowly. Most deposits are Cenozoic to Mesozoic in age, commonly associated with volcanic provinces.

Uses & applications

Used as a gemstone, ornamental carving material, mineral specimen, and abrasive-grade quartz source. Commercial jewelry value depends strongly on color, clarity, cut, and size.

Geological facts

Deep, evenly distributed violet (“Siberian” or “Deep Russian” color) is generally more desirable than pale purple. Heating amethyst can produce yellow citrine or green prasiolite, sometimes intentionally treated.

Field identification & locations

Identify it by its purple color, glassy luster, hardness, and lack of cleavage; it should scratch ordinary glass but not be scratched by a steel knife. Common sources include Brazil, Uruguay, Zambia, Bolivia, Mexico, and the United States.