Attractive and well-formed, this rather large Celestine crystal, and cluster, is classic for Southern Michigan. The main Celestine blade is over 7 cm, with good luster and a lovely, grey-blue color that accents the gemminess beautifully. There are over a half-dozen sharp Celestines in the cluster, and along the bottom there is massive Calcite that exhibits a bright white fluorescence. Interestingly, white fluorescence is uncommon for Calcite, but not at Clay Center. I do not know how and why the Calcite's chemistry is different here, but it sure adds to the interest level for this highly aesthetic cluster that Kay picked up in 1960.