Calcite, Cave-In-Rock, Illinois
Wheat sheaf bundles of parallel growth calcite crystals on a yellow/brown fluorite matrix, from Cave-In-Rock, Hardin County, Illinois. Under short wave UV, the calcite shows a bright blue/white fluorescent response with brief dim phosphorescence. Under long wave UV, the response is a warmer white. The fluorite matrix is poorly fluorescent. This specimen measures 64.1 x 57 x 44.5 mm, and weighs 86 grams.
Under short wave UV (254 nm), the calcite shows a ghostly blue-white fluorescent response.
Creamy, off-white fluorescence is seen under long wave UV (365 nm).
Same specimen shown under visible light.