Fluorite from Bluffton, Ohio
The Midwest is host to a variety of locations that have produced unique fluorite specimens that do not show the typical deep blue fluorescent response under UV. The fluorescence in these fluorites is activated by organic impurities that show a cream to white response, and they are also generally strongly phosphorescent. This is one such specimen. It is from the Bluffton Stone Co. Quarry, in Bluffton, Allen Co., Ohio, and consists of two generations of fluorite crystals; an initial growth of brown/yellow cubes and secondary purple fluorite perched on the older cubes, all on a buff-colored dolomite matrix. Under UV, the older brown/yellow cubes show a bright cream white to yellow/white fluorescence, while the younger purple cubes show only a dim blue/purple response. The fluorite is also phosphorescent, whitish after short wave UV and strong yellow after long wave. The dolomite matrix is also dimly fluorescent and weakly phosphorescent. The size of this specimen is 84 x 58 x 31 mm, and it weighs 131 grams.
Buttery, cream/white fluorescent fluorite cubes to 4mm on an edge, seen under short wave UV (254nm). The dolomite matrix is also weakly fluorescent.
Same view, seen under visible light for comparison.
Gallery images showing a full view of the specimen (top row), and a close-up of the fluorite-containing pocket (bottom row). The image sequence for both views is (left to right): Visible Light, Short Wave UV, Short Wave Phosphorescence, Long Wave UV and Long Wave Phosphorescence. Click on the individual images for a larger view.