mineral

Amethyst (purple quartz), likely with quartz matrix

Quartz, silicon dioxide (SiO₂), purple variety colored mainly by iron-related impurities and irradiation

AI-generated identification · may be incorrect

Visible violet color, translucent edges, vitreous luster, and a conchoidal-to-uneven fracture; quartz hardness is Mohs 7, with no cleavage and hexagonal crystal structure. The pale, rough coating is likely quartz matrix or weathered host material.

Identified August 17, 2026More mineral →

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At a glance

Common name: Amethyst (purple quartz), likely with quartz matrix
Scientific name: Quartz, silicon dioxide (SiO₂), purple variety colored mainly by iron-related impurities and irradiation
Category: mineral
Identified: August 17, 2026
Method: Standard

AI Estimated Value

Approximately $2–$15 for a small common rough fragment; distinctive, strongly colored crystals or locality specimens may sell for $20–$100+.

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 basaltic vesicles; many amethysts formed during the Mesozoic in Brazil and Uruguay, though age varies by locality.

Uses & applications

Used as a gemstone, ornamental specimen, and lapidary material; lower-grade pieces are sold as curios or crushed for decoration. This small rough fragment has modest commercial value.

Geological facts

Amethyst’s purple color commonly results from iron impurities affected by natural radiation. Heating can change it to yellow or orange citrine, but excessive heat may reduce or remove the color.

Field identification & locations

Identify it by purple quartz-like appearance, glassy luster, hardness, and lack of cleavage; a steel knife should not scratch it. Common sources include Brazil, Uruguay, Zambia, and Mexico.