fluorspar meaning in French

n. fluorite, fluorine

In 1852, in his famous paper on the change of wavelength of light, he described the phenomenon of fluorescence, as exhibited by fluorspar and uranium glass, materials which he viewed as having the power to convert invisible ultra-violet radiation into radiation of longer wavelengths that are visible.
En 1852, dans On the change of refrangibility of light, il explique le phénomène de la fluorescence en constatant que certains matériaux, tels que le fluorine (CaF2) et l'ouraline, émettent la lumière visible lorsqu'ils sont exposés au rayonnement ultraviolet, qui possède une longueur d'onde inférieure.