Silica sand
Definition, Composition, Occurrence, and Uses of Silica Sand. Greetings Slim: Sourced from the Appalachians is a reasonable concept. My reason for questioning the provenance is that it is too coarsely skewed to have been wind blown, and it rests high up on the interfluvials – in sheets up to 10 meters deep to have been washed down from the higher elevations.