This is a large cluster of intergrown, prismatic, light golden/smoky colored barite crystals, on a minimal limestone matrix. It was collected in 2016 from the Linwood Mine, Scott County, Buffalo, Iowa. It shows a similar blue/white fluorescent response under all wavelengths of UV, brightest under short and mid wave. It is also phosphorescent, again most brightly following short and mid wave UV. This specimen measures 11.9 x 10.7 x 9.4 cm, and weighs 833 grams.
Located adjacent to the Mississippi River, the Linwood Mine is one of the largest underground limestone mines currently in operation in the United States.
Ghostly blue/white fluorescence is seen under short wave UV (left) and green phosphorescence following exposure to short wave UV (right).
Fluorescence under mid wave UV (left) and phosphorescence following exposure to mid wave UV (right).
Similar blue/white fluorescence is seen under long wave UV (left) and dim green phosphorescence following exposure to long wave UV (right).