Cubic yellow fluorite crystals on limestone matrix, collected in 2016 from a roadcut in Bedford, Indiana. This fluorite shows a very interesting fluorescent/phosphorescent response. Under short wave UV, the cubes fluoresce a bright off-white color, with white phosphorescence. The fluorescent response under long wave UV is a similar bright white, but with green phosphorescence. The largest crystal in these photographs (right of center) measures approximately 6.5 x 5.0 mm.
The fluorite occurrence from which this specimen was collected was confined to a relatively limited area of about 40 yards in length, between knee and head height. Other fluorite specimens were found at this location that showed similar fluorescence, but a markedly different phosphorescent response- blue after short wave UV, but with no visible phosphorescence after long wave UV (see the separate post for an example of this material).