mineral

Amethyst geode or polished amethyst slice

Quartz, SiO₂; purple coloration from iron-related defects and irradiation

AI-generated identification · may be incorrect

Hardness 7 Mohs; purple, translucent to transparent, with vitreous luster and hexagonal quartz crystals lining or comprising the specimen. Quartz has no cleavage, conchoidal fracture, and specific gravity about 2.65; the dark parallel bands may indicate agate or iron-oxide zoning.

Identified September 19, 2026More mineral →

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At a glance

Common name: Amethyst geode or polished amethyst slice
Scientific name: Quartz, SiO₂; purple coloration from iron-related defects and irradiation
Category: mineral
Identified: September 19, 2026
Method: Standard

AI Estimated Value

Approximately $10–$75 for a small common polished specimen; $100–$500+ for large, intensely colored, well-crystallized, or locality-documented pieces.

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

Formed when silica-rich groundwater deposited quartz in volcanic vesicles, commonly during the Mesozoic to Cenozoic; later cutting and polishing produced the flat display face. Exact age and locality cannot be determined from the photograph.

Uses & applications

Used as a decorative stone, lapidary material, jewelry, and mineral-collection specimen; value depends strongly on color saturation, crystal quality, size, and provenance.

Geological facts

Amethyst is the purple variety of quartz and is often associated with gray, white, or reddish chalcedony and druzy quartz. Strong sunlight or heating can fade or alter its color.

Field identification & locations

Identify it by purple quartz, glassy luster, hardness, and lack of cleavage; common sources include Brazil, Uruguay, Zambia, and Namibia. A scratch test should be avoided on polished pieces; inspect for natural crystal texture rather than glass bubbles.