The classic fluorescent mineral, but all fluorites are not luminescent under UV !
Showing here some fluorites with different responses under long wave UV.
Green visible Blue fluo from Gloria 1ª Mine, Córdoba, Andalusia, Spain.
Most common activator: Eu2+ repl. Ca2+
Yellow visible White fluo from Moscona Mine, Solís, Asturias, Spain.
Most common activator: organic impurities.
Purple visible Red fluo from Berbes Mine, Ribadesella, Asturias, Spain.
Most common activator: Related to vacancies in F centers.
Fluorite was one of the first mineral substances investigated by George G. Stokes in 1852, hence the name fluorescence given to the phenomenon.
We can find very diverse responses under the different UV wavelengths, Bluish White, Yellowish White, Pale Yellow, Yellow, Tawn, Red, Violet Pink, Green, Greenish, Violet, Greenish white, Violet blue, Yellowish.
Most Common Activator: Eu2+ Other activators: Organic impurities, Sm2+, Ce3+, Sm3+, Eu3+, Dy3+, Ho3+, Er3+, Tb3+, Pr3+, Nd3+, Yb3+, Tm3+.
Fluorite is a reservoir for many of the rare earth elements. As early as 1881 it was noted that cerium was present in fluorite.
In 1906, Urbain studied the cathodoluminescence of fluorite and attributed the cause of the fluorescence to RRE (yttrium, praeseodymium, samarium, dysprosium, europium, terbium, and also gadolinium and ytterbium in chlorophane); Morse (1907), Tanaka (1924), Nichols (1928), and F. G. Wick also investigated the cause of fluorite's luminescence.
Extracted from: http://www.fluomin.org/uk/fiche.php?id=29&name=FLUORITE