The minerals in the granite are mainly composed of feldspar, quartz, mica, pyroxene, and hornblende. In the structure of the main silicate minerals, each silicon ion is surrounded by four oxygen ions and constitutes a silicon oxide tetrahedron. This basic structural unit is quite stable in nature, strong in acid and alkaline, hard to dissolve, weathered, and good in discoloration.
The decoloration of granite is also different because of the variety of stone. Generally speaking, dark coloured granite is easy to fade. Dark minerals, such as black and dark green, are mainly composed of pyroxene, hornblende, basic plagioclase, magnetite and so on. The light colored granite is mainly acid plagioclase, potassium feldspar, black mica, quartz and so on. Minerals are generally formed in the ground, and some of the minerals are formed first and some later.
The first formation is often the heavier atomic quantity of the vegetarian, the position is deeper, the oxygen supply is less, the pressure is larger, and then the opposite is formed. Therefore, different minerals usually have different forming periods. Their order is roughly: dark mineral: Olivine pyroxene hornblende biotite; light mineral: basic plagioclase acid plagioclase potash feldspar quartz. The minerals formed first are exposed to the surface, because the environment changes greatly, it is easy to produce secondary changes, the late formation of the change is less, the most stable is the quartz.
So it is not one hundred percent to say that marble granite is never fading, but it is important to see the use of the environment and the use and maintenance of the granite.