Unusual Solution Barite from the Linwood Mine, Buffalo, Iowa
The Linwood Mine, an underground limestone mine in Buffalo, Scott County, Iowa, is known for producing beautiful display quality calcite and barite specimens. This location has also produced some interesting fluorescent specimens as well. This is one such piece. It is a roughly triangular, highly etched, single floater crystal of amber-brown baryte from the Linwood mine. This is atypical crystal morphology for the Linwood mine location. As seen in the photographs below, this specimen is brightly fluorescent and phosphorescent under all UV wavelengths. This piece was collected in mid 2017 from a pocket which contained similar specimens of "solution barite" all having a similar etched "dragon skin" appearance and bright fluorescence under UV.
The above photograph show a visible light image of the "solution barite," named for it's highly solution-etched surface. This single, floater crystal measures 60 x 42 x 29 mm, and weighs 142 grams.
Under short wave UV (254 nm), the solution barite shows a bright blue/white fluorescent response.
Following exposure to short wave UV, the solution barite shows bright and lasting pale blue/green phosphorescence/afterglow.
Bright fluorescence seen under long wave UV (365 nm).
Green phosphorescence/afterglow is seen following exposure to long wave UV.