Tim, I have one of those myself. Actually two, both from Leadville. One is more yellow, and the second red. I have a neat sifter that nicely grades the stuff, which turns the big bucket of rock into about 8 smaller jars of now graded rock: I suppose I should just throw away the fines as they are too fine for any use but paint pigment.
The little safety guy inside me wonders, "is this stuff laced with nasties?" I dug my material off the surface, and while I long ago forgot the specifics, I bet my sources had more than a decade of winters to let surface water move the bad stuff further into the pile. But who knows?
This is what is holding up me finishing the Miles Montgomery and Penrose tailings piles.
Keith Hayes
Leadville in Sn3