This specimen of willemite, with the fluorescent view as well, was mined at the Garpenberg Södra Mine, Dalarna County, Sweden.
HANNES GROBE, WIKIMEDIA COMMONS
It is no accident that Franklin, New Jersey, is the “Fluorescent Mineral Capital of the World.” After all, the twin complex zinc-iron deposits of Franklin-Sterling Hill have managed to produce something over 70 minerals that respond to some form of ultraviolet excitation.
But you have to wonder if Franklin, New Jersey town would be so honored to be this specific “capital” if willemite did not respond to ultraviolet excitation. But this reaction is just one of willemite’s essential properties.