I came across a product that might be useful to some modelers:

Repti-Sand, a substrate made for reptile habitats, comes in a black sand form which is perfect for either fine scale coal - having a "freshly mined" or "washed" look complete with tiny, shiny facets, or suitable in a larger scale for cinder ballast.

I found it in Scales'N'Tails, but it is also carried by any pet shop dealing in herps, such as PetsMart or PetCo.

(I just scoop mine right out of one of the snakes' tanks, but that won't work for the rest of you!)

I'd use a scoop with a LOOOOONNNNNNGGGGG handle ! hock: Bob C.