Commercial Use Of Granite

Commercial granites include the aforementioned granite, gneiss, gneiss granite, granite schist, and what scholars call syenite and granodiorite rocks in between. Gneiss rocks include mineral composition, granite-like and granular crystal structure. Commercial granite also includes other similar structures and feldspar crystalline rocks with a small amount of accessory minerals, which are mainly used for decoration, such as plagioclase as petrologists call it. Gneiss is a rough crystalline rock, mainly composed of silicate minerals, showing mosaic and granular crystalline structure. Different types of minerals are arranged regularly or irregularly. According to the American Society for Testing and Materials, granite is classified into ordinary granite and black granite. Ordinary granite is composed of quartz, feldspar, marble, etc., and is black or dark green due to colored minerals. Generally speaking, its color is often influenced by feldspar. The dark green or black rock of black granite is formed by plagioclase, pyroxene, olivine, and hornblende. Therefore, black granite is divided into three types: porphyrite, diabase, and basalt.