Obviously, this doubly-terminated gypsum crystal is from the famous Cave of Swords in Naica, Mexico. It is GEMMY AND TRANSPANRET, ALL THE MORE SO In PERSON. There are some small areas of internal iron staining, but this is quite attractive in person as well. I have seen larger illustrated and even for sale (though not doubly-terminated), but the size combined with the quality and crystallography, is about as good as it gets...and it is still PLENTY big! This is a stunning example of natural crystallography writ large, and because most folks dismiss gypsum as a "cheap" species, it is really a bargain in terms of bang for the buck. This is an old classic of high quality, though, and you should not think they are common.