This specimen is gypsum (a variety of selenite) from the Red River Floodway, Winnepeg, Canada.
The first photo was taken under long wave ultraviolet light. It fluoresces a creamy white under long wave only.
The photo below was taken under short wave UV lighting where it fluoresces a brighter white. Additionally, the specimen will phosphoresce for a few seconds after exposure to either long or short wave UV lights.
Gypsum 
Quantity in Basket: None
Code: CAG-101
Price: $25.00
Shipping Weight: 0.32 pounds
Location: Red River Floodway, Winnipeg, Canada
Minerals: Gypsum (var. selenite)
Size: 1-1/8" x 1-3/4" x 1"