A friend of mine collected extremely fine sand dust from a rock cut
off Interstate 495 where it would blow and collect there. There is real
sand everywhere, and it makes excellent scale sand loads! (He did the
same with iron oxide flakes in a junk yard - fabulous for scrap loads.)

But, yeah, I agree with Elden if you can find AR&M products, they are very
very good. He sells grades from chickpea sizes down to pigment-grade dust.

Tim O'Connor