ASTM C35Full Name ASTM C35 – Standard Specification for Inorganic Aggregates for Use in Gypsum PlasterScope This specification covers perlite, vermiculite, natural and manufactured sand for use as gypsum plaster aggregates.Keywords aggregates; gypsum plaster; inorganic; manufactured sand; natural sand; perlite; vermiculiteResourcesASTM International Website: ASTM C35 Need more info?