Granite
Granite are igneous rocks, very hard, crystalline, and primarily composed of feldspar, quartz accompanied by one or more dark minerals. It is visibly homogeneous in texture. Granite as a hard building stone, finds a great place in building architecture and also has great monumental applications. Due to its hardness, resistance to weathering for decades and centuries , capability to take high gloss , availability in fascinating colors and textural patterns, granite slabs and granite tiles are extremely popular world wide .
The principal characteristics of granite also include high load bearing capacity, crushing strength, abrasive strength, amenability to cutting and shaping without secondary flaws, ability to yield thin and large slabs and - above all - durability.
Physical Properties of Granite
Physically, commercial granites are Hard, Compact rocks with fine to coarse grains of 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 | High resistant |
Chemical Properties of Granite
Chemically, they are igneous 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% |
Uses of Granite
Traditionally the main use of black granite has been as tombstones and other monumental items but with increase in its availability and processing facilities world wide , it has been a promominet dimensional stone used in flooring cladding stair cases , kitchen tops , counters , vanities , basins , in luxury or common household or commercial places.