Does China Blackstone belong to quartzite?

The main mineral components of Blackstone in China are Yingshi, mica and muscovite. According to the classification of petrology, rocks with seasonal as the main mineral component are called quartzite. China Blackstone is actually a dark gray or black granite with mottled texture. Granite is a kind of dark igneous rock, which contains porphyritic minerals such as mica and feldspar, and its main components are quartz and anorthite. Blackstone in China has a distinctive black striped appearance because of its irregular distribution of porphyritic minerals of different sizes and shapes, which is obviously different from ordinary granite. But according to the classification of petrology, it belongs to dark granite, so it still belongs to granite in quartzite in geological properties. Therefore, China Blackstone is a kind of granite with special patterns and belongs to quartzite in a broad sense.