This is a famous variety of mimetite, locally known as campylite. However, this is a most unusual specimen in several regards! Originally the lustrous spheres, to 2.5 cm across, were rich green and then overgrown by a second generation of more typical tan campylite. The green showing through, makes this piece a unique coloration. Scattered about are tiny crystals of pastel blue plumbogummite dating it to the old finds here in the mid 1800s by the association. To top off the specimen there is a single crystal of white Baryte 4.5 cm across extending down the center of the specimen (another rare association). It has the label of Bryce M.Wright (circa 1860), arguably the greatest British mineral dealer of the heyday of these mines. It was later obtained in a museum exchange and long held in the Ralph Sutcliffe collection, and retains his label too. Greenbank acquired the Sutcliffe collection in 1991 and held this himself for nearly 20 years until now. Illustrated in the Greenbank Collection book, page 632, as a full page photograph. Most viewers of the collection consider this to be one of the most interesting and memorable of the large and diverse campylite/mimetite suite here, which was extensive (dozens of specimens!) .