This is one of the most rare crystal habits for boleite, and comes from the early 1970s exploration there by Ed Swoboda with Bill Larson. 1 in 100 crystals have this more complicated shape, while others are simply cubic. And, this is perfect, complete all around, balanced on a bit of matrix, and so amazingly sharp that it looks carved! From the award-winning thumbnail collection of Sharon and William Panczner, author of the book Minerals Of Mexico, and last seen and exhibited in the 1960s.