Pearlescent, highly lustrous, diaspore plates in nifty juxtaposed angles on a thin crust of matrix form a very showy specimen on this old-time piece from the Chester Emery Mines of Massachusetts. Diaspore is an uncommon aluminum hydroxide and this is highly representative of the species and famous locale. The color is very good for the material, which is rarely seen today. Comes with an old, faded, expertly handwritten label. The collection this came out of was a museum stash dating to prior to World War I.