One of the main ingredients of cement, high quality gypsum is supplied by AvinTrading as dehydrate (CaSO4 2H2O), monohydrate (CaSO4 1H2O) or hemi hydrate (CaSO4 ½ H2O). Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O.It is widely mined and is used as a fertilizer, and as the main constituent in many forms of plaster, blackboard chalk and wallboard. A massive fine-grained white or lightly tinted variety of gypsum, called alabaster, has been used for sculpture by many cultures including Ancient Egypt, Mesopotamia, Ancient Rome, the Byzantine Empire and the Nottingham alabasters of Medieval England. Mohs scale of mineral hardness, based on scratch hardness comparison, defines hardness value 2 as gypsum. It forms as an evaporite mineral and as a hydration product of anhydrite.
Limestone is the main raw material for clinker and additive ingredient for cement. Limestone is a sedimentary rock, composed mainly of skeletal fragments of marine organisms such as coral, forams and molluscs. Its major materials are the minerals calcite and aragonite, which are different crystal forms of calcium carbonate(CaCO3).