Take pearlescent pigments as an example, pearlescent pigments are a class of pigments with pearl luster, which are deposited on the substrate (generally natural mica, synthetic mica, glass sheet and other sheet-like materials) above a layer or alternately deposited multiple layers of metal oxides or non-metallic oxides and formed a flat sandwich body with a structure similar to sandwich. Due to the difference in refractive index between the substrate and the oxide deposited on its surface and each oxide, when the light shines on the surface of the pearlescent pigment, the incident light will be refracted and reflected at the interface of each layer of the pearlescent pigment, and the color of the pearlescent pigment that people see is the result of the superposition of light after multiple refractions and reflections of the light, that is, the interference phenomenon of light.

Mica has a wide range of uses, in ancient China, it is often used to do traditional Chinese medicine, the ancients even think that taking mica: a year to remove all diseases (heavy metal poisoning), three years of long service, husband into a boy (body scrap), Zhongshan uncle Qing suit, over time can become a cloud (soul ascension). However, in the era without glass, the transparency of mica makes it a better decorative material, for example, we are familiar with the mica screen candle shadow deep, the river gradually falling Xiaoxing sink. Mica screen is low, tassel tent is small and mica calf car.