Ordinary portland cement also known as OPC 42.5 is most widely used cement. It is grey coloured microfine powder.Gujarat is geographically situated on quality gypsum bed. Lots of Quality Gypsum is available in gujarat which is a basic raw material for Cement. We have various grade quality cement as per BS EN 197 standards and other respective standards for other types of cement. Portland cement (often referred to as OPC from Ordinary Portland Cement) is the most common type of cement in general use around the world because it is a basic ingredient of concrete mortar stucco and most non-specialty grout. It is a fine powder produced by grinding Portland cement clinker (more than 90%) a limited amount of calcium sulfate (which controls the set time) and up to 5% minor constituents as allowed by various standards such as the European Standard EN197-1:Portland cement clinker is a hydraulic material which shall consist of at least two-thirds by mass of calcium silicates (3 CaOA.SiO2 and 2 CaOA.SiO2) the remainder consisting of aluminium- and iron-containing clinker phases and other compounds. The ratio of CaO to SiO2 shall not be less than 2.0. The magnesium oxide content (MgO) shall not exceed 5.0% by mass.ASTM C 150 defines portland cement as "hydraulic cement (cement that not only hardens by reacting with water but also forms a water-resistant product) produced by pulverizing clinkers consisting essentially of hydraulic calcium silicates.