mineral

Green glassy mineral fragment, possibly fluorite

Fluorite (calcium fluoride, CaF₂), tentative identification

AI-generated identification · may be incorrect

Small translucent vivid-green fragment with a vitreous luster and likely irregular fracture; fluorite has Mohs hardness 4, cubic crystals, perfect octahedral cleavage, and specific gravity about 3.18. The image is insufficient to exclude man-made green glass or another mineral such as prehnite, peridot, or uranium-bear…

Identified August 30, 2026More mineral →

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Physical properties

Formation & geological history

Green fluorite forms in hydrothermal veins, commonly with quartz, calcite, and barite, and is generally Paleozoic to younger depending on the deposit. Fluorite is geologically plausible around central Hesse, Germany, though the specimen cannot be localized confidently from the photo.

Uses & applications

Fluorite is used as a flux in steel and aluminum production, in hydrofluoric-acid manufacture, and as a collector or gemstone specimen; transparent pieces may be faceted, though they are relatively soft. Common fragments are usually worth about $1–$10; attractive crystals or gem-quality material may range from $20–$200+.

Geological facts

Strong green color can result from trace rare-earth elements or radiation-related defects. Fluorite commonly fluoresces blue, violet, or green under ultraviolet light.

Field identification & locations

Check for cubic/octahedral cleavage, hardness below glass, and density; a scratch test and UV response are useful but not definitive. If it has perfectly smooth conchoidal fracture and no cleavage, green glass is more likely; do not heat or abrade it until confirmed.