The term “fluorescence” was derived from the mineral fluorite, where the phenomenon was first observed. Since then, over 500 minerals have been identified to exhibit some form of fluorescence. While only between 10 and 15 percent of all minerals fluoresce, some are much more common than others. Calcite is probably the most common and can fluoresce in a variety of colors. Aragonite, sodalite, scheelite, willemite, opal, scheelite and barite are examples of other fairly common fluorescent minerals. Click the link for a gallery common fluorescent minerals.