Marble is a common stone used in home decoration. It is loved by the majority of people for its changeable colors and beautiful patterns. However, during use, marble often suffers from problems such as fading and dull luster. So why does marble fade?
Marble background wall
First of all, we need to understand what marble is?
Marble is a metamorphic rock formed from the original rocks in the earth's crust through the action of high temperature and high pressure in the earth's crust. The internal force of the earth's crust promotes the process of qualitative changes in the original rocks. Qualitative change refers to the change in the structure, structure and mineral composition of the original rock. The new rock type formed after qualitative change is called metamorphic rock. Marble is mainly composed of calcite, limestone, serpentine and dolomite. Its main component is calcium carbonate, accounting for more than 50%. Others include magnesium carbonate, calcium oxide, manganese oxide and silicon dioxide.
Marble Mine
Marble is mainly composed of calcite, dolomite and other minerals. The molecular formula of calcite is CaCO3, and dolomite is CaMg[CO3]2. Both have carbonate [CO3] ions, which are relatively active and are easily affected by sulfur dioxide in the air to form gypsum (Ca[SO4]· 2H2O), this plaster In the form of turbid particles. Calcite easily reacts with water to form calcium bicarbonate (Ca[HCO3]2) dissolved in water, which turns into calcium carbonate (calcite) after the water is lost (this is how caves, stalagmites, and stalactites in limestone areas are formed) .
stalagmite
After these changes, the original crystal polished surface of the marble polished slab no longer exists. After losing its protective layer, marble is particularly prone to discoloration and fading. Therefore, marble is not suitable for exterior wall decorations, especially open-air decoration materials. Marble used as exterior wall decoration generally fades in color after 2 to 3 years.
marble template
