preserving bichirs

Can someone PLEASE PLEASE PLEASE tell me where to buy red sand for Bichir dinosaur fish I have been looking EVERYWHERE I live in Arizona btw!

I get a lot of specimens donated to me from shops and other hobbyists as I like to preserve and display them. This method only works with armoured fish, such as Polypterids, Gars and Bowfin. The reason why I do this is because I get to find out how a fish has died, I learn about their anatomy...