(a)[ "cement" means any variety of cement manufactured in India, and includes portland pozzalana cement, blast furnace slag cement, water-proof (hydrophobic) cement, rapid hardening cement, low heat cement, masonry cement and [high strength ordinary portland cement] [Substituted by S.O. 562 (E), dated 30th September, 1975.] but does not include oil-well cement and which and coloured cement (other than grey portland cement;
