Explanation
A metamorphic rock with gneissose structure and rich plagioclase, it is the most common rock type in gneiss. It is mainly composed of intermediate acid plagioclase, quartze, biotite, ordinary amphibole, pyroxene, etc. It is the product of intermediate and high grade metamorphism of intermediate acid intrusive rocks, volcanic rock or hard sandstone.
Classification
Natural materials and products -> Mineral materials