Should this crystal skull ever come on the market who knows what it would cost. Tiffany stone is very rare and it rarely comes out of the mine in big enough nodules enough to make something as large as this one. I do have smaller skulls and angels made from the off cuts, but this one is not for sale. Bertrandite is extracted from this stone to make the lightest metal known to man for use in missile and spacecraft construction.  The stone has fluorite and opal amongst its construction, but they have a distinctive purple mix woven into them. However the skull is here for my own use and will never be sold, in fact my source for the rock has dissappeared as quickly as it came to me.