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Physically, commercial granites are Hard, Compact rocks with fine to coarse grains of metamorphic or igneous origin. | Hardness: | 6 to 7 on Moh's Scale | | Density: | 2.6 to 2.8 Kg/cm3 | | Compressive Strength: | 140 to 210 N/mm2 | | Modulus of Rupture: | 15 to 25 N/mm2 | | Water Absorption: | 0.1-0.6% | | Average Wear: | Less then 1% | | Porosity: | Quite low | | Weather Impact: | Resistant | Chemically, they are igneous/metamorphic rocks composed of quartz, feldspar & ferromagnesian minerals like kriolite, chlorite, garnet, etc. A typical granite will have following chemical composition: | Silica (SiO2): | 70-75% | | Al2O3: | 10-15% | | CaO+MgO: | Less then 0.5% | | FeO + Fe2O3: | 2-4% | | Alkalies: | 4-6% | | TiO2: | Less then 0.5% | | Loss On Ignition (LOI): | Less then 0.5% | |