Esperite is a fantastically rare mineral that fluoresces a bright canary-yellow under 254 nm UV light. Found only in two locations worldwide. This piece is from the type location, the find from which it was named, and only location it appears larger than microcrystals. It is one of the largest Esperite dominant specimens we have ever seen. Parker Shaft, Franklin Mine, Franklin, New Jersey. 4" x 2" x 2.5", 11.7 oz.