Unusual Fluorite from Le Muy, Draguignan District, France
Contributed by: Michael Crawford
Date: Sep 30th, 2026
Locality: Draguignan, Var, Provence-Alpes-Côte d'Azur, France (See on Mindat)
Size: 8 x 13 cm
Description:
This is a fluorite specimen from Le Muy, Draguignan District, Var, Provence-Alpes-Côte d'Azur, France. Specimens of this unusual fluorite were found during the excavation for the construction of a house. Only a few of these "sugar cube" fluorites were extracted (personal communication from Daniel Montero). This specimen fluoresces differently from most fluorite. Under longwave (365 nm LED) and 340 nm LED illumination, it appears light blue; under midwave (305 nm LED) and shortwave (255 nm LED) illumination, it appears white. The light blue, fluorescent fluorite cubes overgrow clear-to-white fluorite that exhibits the typical violet-blue fluorescence.
Longwave emission spectra for both types of fluorite peak at 422 nm. This emission is caused by europium (Eu2+) impurities replacing some calcium (Ca2+) in the fluorite structure. The light-blue-fluorescing fluorite contains a second activator that contributes blue, green, and yellow emission. The difference between light blue and violet-blue emission spectra is a broad peak with a maximum at 463 nm. This difference suggests that the second activator is organic.
Under midwave and shortwave illumination, the europium-activated violet-blue fluorescence disappears, leaving only off-white fluorescence from organic activation. This fluorescence is much dimmer than the longwave response. There is no afterglow from exposure to any wavelength of UV light.
Summary of luminescence responses:
Fluorite (Mindat) (RRUFF)
- Fluorescence under Longwave (365nm LED) UV light: Blue
- Fluorescence under 340nm LED UV light: Blue
- Fluorescence under Midwave (305nm LED) UV light: White
- Fluorescence under Shortwave (255nm LED) UV light: White