Granodiorite

Classification：Igneous Rock

A medium acid deep rock, which is the main component of plagioclase, is similar to granite, and the quartz content is more than diorite, which is the intermediate type of transition from granitoid to diorite.

Granodiorite is a kind of acidic phaneritic rocks. It is an important species of granitoid rocks. It is an intermediate type of granitoid to diorite.

Characteristics and distribution:
Granodiorite is a kind of magmatic rock with coarse-grained, plagioclase content, alkaline feldspar content, silica content of about 56%, and quartz content of more than 20%. The main associated minerals are copper, iron, and so on. Granodiorite is widely distributed on the earth. 34% of igneous rocks in the earth's crust are Granodiorite. They are distributed on all continents.
It is difficult for ordinary people to distinguish Granodiorite from granite, so Granodiorite is often referred to as granite in shops. Therefore, the most important characteristic of the identification is that the plagioclase is more than the potassium feldspar. Generally, the plagioclase is about 2/3 of the total feldspar, while the dark minerals are mainly hornblende and some are black mica. Quartz content is generally less than that of granite. It is an intermediate acid rock which is granite overturned to diorite.

Mineral composition:
Granodiorite is more plagioclase and dark minerals than granite (plagioclase is more than potash feldspar, while granite is opposite), so the color of rock is a little deeper than granite, and it is gray green or dark grey. Plagioclase minerals accounted for 65-90% of the total, is generally acidic and neutral plagioclase, often with obvious zoning structure. Quartz content is less than granite, generally around 25%. With more dark colored minerals hornblende, accessory minerals are titanite, apatite, magnetite, zircon, allanite and monazite etc.. Common subhedral granular texture, porphyritic structure.

Growth environment:
Granodiorite is often associated with granite, which is seen in the center of granite rock mass or the edge phase of the rock mass, and some of them are produced by separate rock masses, which are sometimes large and form rock foundations. Such as the famous north of the Sierra Nevada batholith is mainly composed of Granodiorite. Xiuning rock mass, Beijing Zhoukoudian rock mass and Jiangsu high rock mass in Anhui, China are also made up of Granodiorite alone. The material features of Granodiorite are similar to those of granite. It can be processed by various means and can be polished. [1]

Processing history:
Granodiorite has been processed from ancient times. In the Empire of Rome, it was an expensive raw material, such as being exploited in Egypt. Because it is relatively strong, it is generally used as the surface of the ground, stairs, the surface coverage of buildings and the surface of streets. Granodiorite is the lightest igneous rock. It may represent the composition of all kinds of rocks in the continental crust.