XL 4
This is a piece of Calcite, Smithsonite, and Hydrozincite from the Kelly Mine, Magdalena, New Mexico.  The Calcite is red, Smithsonite is violet, and Hydrozincite is white/blue under shortwave UV.  This is a very nice arrangement but be aware that it requires a strong lamp to bring out the colors effectively.  Dimensions are 7 x 5 x 3 inches.  Weight is 13 lbs.  Price: $100.