One of the things that can turn people on to minerals and mineral collecting is seeing minerals take on unexpected colors when exposed to ultraviolet (UV) light. Shown below are pairs of pictures of some of Wisconsin’s fluorescing minerals—plain light on the left, shortwave ultraviolet (UV) light on the right.
Click on images to enlarge, click on mineral names to read more.
CALCITE Calcite cleavage, from near Fountain City, Wisconsin. Specimen is about 8 cm across. (Images by Harold Moritz.)
FLUORITE Cubic crystals on chert, from Sturgeon Bay, Wisconsin. Specimen is about 4 cm across. (Images by Harold Moritz.)
HYALITE Crust of hyalite opal on granite from Koss Pit, near Wausau, Wisconsin. Specimen is about 16 cm across. (Images by Harold Moritz.)
MANGANOAN CALCITE Manganoan calcite crusts on hematite from the Montreal Mine, Iron County, Wisconsin. Specimen is about 10 cm across. (Images by Harold Moritz.)
POTASSIUM FELDSPAR and ZIRCON Brown zircon crystals on potassium feldspar, from Zunker’s Pit, near Stettin, Wisconsin. Under UV light, the zircon glows yellow and the potassium feldspar fluoresces pink. Specimen is about 4.5 cm across. (Images by Harold Moritz.)
STRONTIANITE Spherical aggregates of white strontianite on dolostone, from Mackville, Wisconsin. Specimen is about 4 cm across. (Images by Harold Moritz.)
