No, it causes impactions which can lead to death. Not worth your money whatsoever. It also dries up Leopard Geckos' feet, so their shed will get stuck on. Toes can fall off from this, so the sand is definitely a no-no.

Slate tiles look great and work well for the Leopard Geckos. Cresteds you can just keep using Bed-A-Beast, paper towels, etc.