A unique, old-time calcite specimen from the Joplin Field of Missouri. This weirdly shaped, conical piece is called a "harlequin" or masked calcite. A glassy, translucent, amber calcite scalenohedron has an overgrowth crust of bone-white aragonite. The aragonite masks the calcite, just as a Harlequin, a comic character in pantomine, wears a mask. A very unusual specimen from a very uncommon mine - the Blue Goose, in this historic district. Ex. Norris, Steve Chamberlain and George Feist Collections.