Fluorite, Pugh Quarry, Custar, Ohio
The Pugh Quarry is a large open pit limestone operation located near the town of Custar, in Wood County, northwest Ohio, and has been a notable source for well-formed and aesthetic, amber to golden colored calcite crystal specimens. Less commonly, fluorite specimens have also been found at this location. The example shown here features transparent, light tan cubes of fluorite with darker, root beer brown centers, on a grey colored fossiliferous limestone matrix. As seen in the photographs below, the fluorite is brightly fluorescent under UV and shows strong phosphorescence.
Fluorite from the Pugh Quarry, shown here under visible light. Note the dark, root beer brown centers of the fluorite cubes. The size of this specimen is 64 mm x 61 mm x 34 mm, and it weighs 150 grams.
As shown in the photo montage above, this specimen shows bright fluorescence under short wave (254 nm) and long wave (365 nm) UV. Following exposure to UV, this fluorite is also strongly phosphorescent.
This fluorite cluster shows an interesting phenomenon following exposure to long wave UV (365 nm). Immediately after shutting off the UV source, the resulting phosphorescence/afterglow is distinctly pale yellow. However, as the afterglow begins to fade, the color shifts to green. This photo montage illustrates the phenomenon. Image at far left shows fluorescence under LW UV. The middle image was taken immediately after shutting off the LW source. The image at far right was taken after waiting approx. 5 seconds after shutting off the UV source. Note the color shift of the afterglow from yellow to green.