Aragonite on Calcite, w/ Sulfur - Italy
Every time I photograph one of these specimens I'm struck by the detail and beauty. Vividly fluorescent but it doesn't stop there; the fluorescent response changes under each wavelength. And it's extremely phosphorescent to boot (see the pic below, no lights at all). If there were a contest for the classiest fluorescent mineral - as much as I like Greenland - this would make it a hard decision for me.
La Grasta Mine, Sommatino, Caltanisseta, Sicily, Italy