Calcium Silicate is a hydrous or anhydrous silicate with varying proportions of calcium oxideand silica. many different calcium silicates occur in nature in mineral form (e.g.,wollastonite, afwillite, grammite). The stoichiometry of the hydrate in cement paste is variable and the state of the chemically and physically bound water in its structure is not clear. Thus, calcium silicate can be prepared by calcining the oxide with silica, SiO2, at an elevated temperature: CaO + SiO2+ heat→CaSiO3. Calcium orthosilicate is commonly used as a safe alternative to asbestos for high-temperature insulation materials. Industrial grade piping and equipment insulation are often fabricated from calcium orthosilicate.