Potter-Cramer Mine 2

 
From the Potter Cramer Mine, near Wickenburg, Arizona, this is a nearly solid face of the previously unknown "cornflower blue" mineral described in Manuel Robbins' book.  The mysterious mineral turned out to be a common one, Chalcedony, but with a very uncommon fluorescent response.  This piece has nearly a solid face of the blue Chalcedony along with some druzy Quartz in the middle and a few small spots of green Hyalite.  The host rock is a red Feldspar that can barely be seen along the right edge.  An unusual and rare piece.  Shown under shortwave UV.  Moderate brightness.  This piece is valuable primarily for its rarity rather than its display value.  Dimensions are 4 x 1 1/2 x 1 inches.  Price: $25