I found two things at Michaels that might be helpful to all you diorama fans out there.The first is called Deco Art ,sandstone. It comes in a small plastic jar, brushes on, and leaves a dirty or gravel like texture. The second is an acryllic paint by Delta Creative.It's labeled Ceramacoat, and is a red iron oxide color. I used it mixed with other different colors, and straight, and it looked pretty good.Hope this helps .