Fluorite was discovered last summer by the writer while examining the galena limestone quarries at Neenah, Wisconsin, when on a field excursion with the geological students of Lawrence College. Since this mineral has never been mentioned as occurring in the Ordovician of this State, and also because its apparent absence has been the repeated cause for especial mention in various State geological reports, it seems worth while to call attention to this discovery.
Prof. J. D. Whitney,2 in discussing the minerals of the “lead region” in 1862, gives the following description of fluor :
“The element fluorine seems to be very scantily and irregularly distributed through the Paleozoic rocks of the Northwest. Even where these have been partially metamorphosed by igneous agencies, as on Lake Superior, fluorspar is of very infrequent occurrence ; indeed, we are not aware of its having been discovered in more than . . .