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.