A large specimen of naturally fluorescent Andersonite. It glows in the sun and turns green and switches back to yellow under fluorescent lights. The crystals exhibit an efflorescent look perhaps from a coating of gyspsum, which protects the Andersonite. A rich, beautiful, specimen once in the collection of the late and famous Thomas McKee, a collector who built the finest mineral collection in Arizona during the 1970's. See McKee's label under the prov. tab.