About Granite
Granite, from igneous rock, is a very hard, crystalline, and primarily composed of feldspar, quartz accompanied by one or more dark minerals. It is visibly homogeneous in texture.
The term "Granite" means "grain" in Latin word "Granum" because of its granular nature.
Granite is the hardest building stone, and granite slabs and granite tiles occupy a prominent place among dimensional stones. Due to its hardness, resistance to weathering, capability to take mirror polish, fascinating colors and textural patterns, granite slabs and granite tiles are extremely popular.
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.
Due to highly dense grain, it is impervious to stain. Polished granite slabs and granite tiles have achieved a special status as building stones globally. Granite is also used for wall cladding, roofing, flooring, and a variety of other interior and exterior applications.
India is one of the largest producers of granites blocks and processed granite slabs and granite tiles. Granites from leading Indian exporters are listed here.
Physical Properties of Granite
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 |
Chemical Properties of Granite
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% |
Uses of Granite
- Roadstone, building blocks, but has poor resistance to fire as it crumbles when exposed to intense heat.
- Traditionally the main use of black granite is in tombstones and other monumental items, and to a lesser extent for various types of counters, especially in the financial world, decorative applications, elegant trimmings and luxury floorings.
- Stones on bolo cord slides and pendants, paperweights, bookends, lazy susan turntables, etc.
Ocurrances of Granite
India |
Chimakurthy Mandal, Prakasham Dist, Andhra Pradesh |
China |
Shanxi and Shandong |
Brazil |
Giallo Veneziano quarry |
Scotland |
Bunessan , Ross of Mull |
Latin America |
Suriname |