This is a brightly fluorescent cluster of root beer brown colored fluorite cubes, with white bladed celestine crystals, from the Graymont Quarry, Genowa, Ottawa County, Ohio. The bright fluorescent response is activated by organic inclusions in the fluorite crystals. Many of the root beer fluorites from the Findlay Arch district of northwestern Ohio show a similar fluorescent response under UV, but this specimen is the brightest I've encountered. The size of this specimen is 55 x 41 x 25 mm, and it weighs 55 grams.
The Graymont Quarry (aka Graymont Dolime Quarry, Genoa Quarry) is a well-known producer of beautiful fluorite specimens. This active quarry has been in operation since the late 1800's, and produces lime products and construction aggregate.
In the above photograph, bright, nearly pure white fluorescence is seen under short wave UV (254 nm).
As shown above, pale blue-green phosphorescence is seen following exposure to short wave UV (254 nm).
The brightest fluorescent response of this specimen is seen under long wave UV (365 nm). As shown above the long wave response is a warmer, yellow-cream color.
As shown above, pale yellow phosphorescence is seen following exposure to long wave UV (365 nm).
Same specimen shown under visible light. Cluster of translucent, root beer brown fluorite cubes with white bladed crystals of celestine.