mineral

Pale green glassy mineral fragment, possibly prehnite or fluorite

Probable prehnite (Ca₂Al₂Si₃O₁₀(OH)₂) or pale-green fluorite (CaF₂); exact identification requires testing

AI-generated identification · may be incorrect

Translucent pale green, vitreous to pearly luster, irregular fracture with possible cleavage; prehnite hardness 6–6.5, fluorite hardness 4. Color and texture are consistent with either, but the photograph is insufficient for certainty.

Identified August 22, 2026More mineral →

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At a glance

Common name: Pale green glassy mineral fragment, possibly prehnite or fluorite
Scientific name: Probable prehnite (Ca₂Al₂Si₃O₁₀(OH)₂) or pale-green fluorite (CaF₂); exact identification requires testing
Category: mineral
Identified: August 22, 2026
Method: Standard

AI Estimated Value

About $1–$10 for a small unidentified fragment; $10–$100+ for well-crystallized, attractive, or fluorescent specimens.

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

Prehnite commonly forms in low-temperature hydrothermal cavities of basalt and other volcanic rocks; fluorite forms in hydrothermal veins. Both are generally geologically young relative to Earth’s oldest rocks, with age depending on the host deposit.

Uses & applications

Attractive specimens may be collected or cut as decorative stones; fluorite is also an important industrial source of fluorine. Prehnite has limited industrial use and is mainly ornamental.

Geological facts

Prehnite often occurs as botryoidal or radiating aggregates and may show a distinctive soft, waxy appearance. Fluorite commonly forms cubic crystals and can fluoresce under ultraviolet light.

Field identification & locations

Check hardness: a steel knife scratches fluorite but usually not prehnite; examine cleavage and crystal shape, and test fluorescence. Common localities include India, Australia, South Africa, China, Mexico, and the United States.