Green Willemite and white-tan Smithsonite -as described in Robbins (1994). Willemite covers about half of the surface of the specimen and consists of several crystals (most of them sub-millimeter). There are several cavities/vugs.
Smithsonite covers the other side. Hundreds of white and tan crystals of about 1mm fluoresce a vivid blue under SW. Purple hue is also evident. MW and LW are not significant. Strongly phosphorescent after SW. Purchased at the Vienna Mineral show for 20E. (<gasp>)
Size: 80 x 50 x 35 mm
(Photos by, and from the collection of Stefano Barbara)
White light side2