Granite

Word granite comes from the Latin granum, a grain, is an igneous rock and is formed from magma. Indian Granite is massive, hard and tough, and therefore it has gained widespread use as a construction stone. Granite has been extensively used as a dimension stone and as flooring tiles in public and commercial buildings and monuments. Polished granite is also a popular choice for kitchen countertops due to its high durability and aesthetic qualities. It comes in many natural colors depending on their chemistry and mineralogy.




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%