mineral
Polished Tumbled Fluorite (or Dark Amethyst)
CaF2 (Calcium Fluoride) / SiO2 (Silicon Dioxide)
Hardness: 4 (Fluorite) to 7 (Quartz/Amethyst) on the Mohs scale. Color: Deep purplish-gray, dark violet, with subtle swirling color patterns. Luster: Vitreous to silky resinous when polished. Crystal Structure: Isometric (Fluorite) or Hexagonal (Amethyst).…
- Hardness
- 4 (Fluorite) to 7 (Quartz/Amethyst) on the Mohs scale
- Luster
- Vitreous to silky resinous when polished
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Physical properties
Hardness: 4 (Fluorite) to 7 (Quartz/Amethyst) on the Mohs scale. Color: Deep purplish-gray, dark violet, with subtle swirling color patterns. Luster: Vitreous to silky resinous when polished. Crystal Structure: Isometric (Fluorite) or Hexagonal (Amethyst). Cleavage: Perfect octahedral (Fluorite) or no true cleavage (Amethyst).
Formation & geological history
Formed in hydrothermal veins and cavity linings within igneous and sedimentary environments where fluoride- or silica-rich fluids cooled and crystallized over thousands to millions of years.
Uses & applications
Popular for lapidary arts, palm stones, worry stones, pocket specimens, decorative rock collections, and metaphysical or crystal healing practices.
Geological facts
Fluorite exhibits strong fluorescence under UV light, a property that was actually named after the mineral itself. Dark purple quartz varieties like amethyst gain their deep color from natural irradiation affecting trace iron impurities.
Field identification & locations
Identified by its smooth, polished, rounded surface and dark plum to deep purple coloration with mottled tonal variations. Commonly sourced from China, Brazil, Mexico, and South Africa. Collectors look for rich color intensity, absence of internal fractures, and a high-gloss finish.
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