Granite

Granite: Magmatic intrusive rock, with potassic an acid chemism, made up of quartz potassic feldspar, mica and accessory minerals, plagioclase, Any compact rock which is strong and can be, polished, whose hardness exceeds the values of 4/4.5 on the Mohs scale. Commercially, the term 4.5 on includes almost all magmatic rock.