Fluorescent Calcite and Pyrite crystals mineral specimen from Madan in Bulgaria 

Here is a delightful example from the Madan ore field in Bulgaria consisting of well formed UV reactive Manganoan Calcite crystals with wonderful formations and which glow a delightful sweet bright neon watermelon pink to coral pink color under long wave ultraviolet light combined with shiny golden Pyrite crystals
Madan, in the Rhodope Mountains of Bulgaria, just north of the frontier with Greece, is an ancient ore-miners’ settlement. The history of mining in the Madan region extends back at least as far as the Thracians in the fifth century B.C. where the extraction of lead ore began.
Please note : Fluorescence is a phenomenon that causes a mineral to "glow" within the visible spectrum when exposed to ultraviolet light. Ultraviolet light is a form of electromagnetic radiation invisible to the human eye. The ultraviolet reaction is only visible with a special fluorescent torch / lamp with a filter that blocks white light but allows ultraviolet light to pass through. In order to achieve satisfactory results, do not use inexpensive 'UV' lights. Keep in mind that not only wattage, filtration but also distance from the UV torch to specimen are significant factors for best results.
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