This large and aesthetic barite specimen was collected from the Linwood Mine, Buffalo, Scott Co., Iowa from a find made in November 2019 called the "Skunk Pocket." The Skunk Pocket is notable for the brightness and unique pattern of fluorescence of the barite specimens it produced. Consisting of yellow-amber colored prismatic crystals, the barite specimens from the Skunk Pocket are distinct in that some of the crystal faces have a thin secondary barite deposit on their surface, giving them a frosted appearance. Under all UV wavelengths, these frosted surfaces show a preferential bright blue-white fluorescent response, with strong and lasting phosphorescence. The central face of each prism has no secondary barite coating, and is therefore not fluorescent, producing a striped pattern under UV that is reminiscent of a striped skunk, thus providing the suggestion for the name of the "Skunk Pocket." This specimen measures 17.4 x 14.5 x 10.2 cm and weighs 2.43 kg (5.35 lbs.).
Located adjacent to the Mississippi River in Scott County, Iowa, the Linwood Mine is one of the largest underground limestone mines currently in operation in the United States.
The skunk barite specimen showing bright blue-white fluorescence under long wave UV (365 nm). Note the preferentially fluorescent crystal faces with the central non-fluorescent surface, giving rise to the name of the "Skunk Pocket."
As shown above, after the long wave UV source is turned off, bright and lasting green phosphorescence is seen.
Similar blue-white fluorescence is also seen under short wave UV (254 nm), but not as bright as the long wave UV response.
Following exposure to short wave UV (254 nm), pale blue-green phosphorescence is seen.
Same specimen shown under visible light. Note the frosted crystal faces resulting from secondary barite deposition.