Granite is a common type of intrusive, felsic, igneous rock which is granular and phaneritic in texture.
A worldwide average of the chemical composition of granite, by weight percent:
| SiO2 | 72.04% (silica) |
| Al2O3 | 14.42% (alumina) |
| K2O | 4.12% |
| Na2O | 3.69% |
| CaO | 1.82% |
| FeO | 1.68% |
| Fe2O3 | 1.22% |
| MgO | 0.71% |
| TiO2 | 0.30% |
| P2O5 | 0.12% |
| MnO | 0.05% |
It is not easy to measure the hardness of Granite. Granite is a rock composed of multiple minerals, typical Quartz, Feldspar, Biotite and Hornblende. Each of the minerals has a unique hardness. In other words, we can measure the hardness of individual material but not easy of granite as a rock.