This extreme rarity is not only aesthetic on its own merits, quite lustrous and with a pineapple-like color to it that is unusually good for the species; but it is also the finest example of the species known, by an order of magnitude. It is considered to be one of the great treasures of the Romero collection. Once a core specimen on display in both his museum, and later for a decade in the University of Arizona Mineral Museum on loan from the Romero family. Featured in the book on Romero's collection, on page 30. Jeff Scovil photo