XL 5
This is a piece of Calcite with a bubbly coating of Aragonite from the Glove Mine, Santa Rita Mtns, Arizona.  Under shortwave UV the Aragonite glows bright green due to the presence of Uranium salts.  An additional feature of this piece is that there are zoned areas of fluorescence.  Some of the green is fairly solid but some are small blebs on a dark background.  Dimensions are 14 x 7 x 4 inches.  Weight is 26 lbs.  Price: $125.