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 blue phosphorescence. The fluorescent response under mid and long wave UV is a similar bright white, but without visible phosphorescence. The crystals seen in these photographs measure up to 2.5 mm on edge.
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- white after short wave UV and green after long wave UV (see the separate post for an example of this material).
The above images show fluorescence under short wave UV (top) and blue phosphorescence following exposure to short wave UV.
The fluorescent response under long wave UV is very similar to that seen under short wave, but without phosphorescence.
Visible light photograph of the same specimen. The largest crystals measure approximately 2.5 mm on an edge.