Despite the many advantages of mica pigments, their use in cosmetics has raised ethical concerns due to the mining practices involved in extracting the mineral. Much of the mica used in the cosmetic industry is sourced from regions where labor practices are problematic, including child labor and unsafe working conditions.

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.

In these factories, technological advancement coexists with traditional practices. Automation plays a significant role in enhancing efficiency and minimizing human error, yet the human touch remains indispensable. The calibration and programming of machinery are the realms of engineers who bring their authoritative knowledge to bear, bridging the gap between mechanical processes and material science.

Natural mica powder and synthetic mica powder also have great differences in electrical insulation, mechanical properties, chemical stability, application range and cost. Natural mica powder has good electrical insulation, but the volume resistivity is lower than that of synthetic mica. Synthetic mica powder has better electrical insulation properties, high volume resistivity and stable dielectric constant, and is suitable for high performance electrical insulation materials. The hardness of natural mica powder is relatively low (2-3), and it has good elasticity and peeling property. The hardness of synthetic mica powder is higher (between 3 and 4), and the tensile strength and compressive strength are better than that of natural mica powder. Natural mica powder is stable in acid-base solution, but it is easy to decompose at high temperature. Synthetic mica powder is stable to acid and base at room temperature, but will be slowly corroded by sulfuric acid above 300℃. Better thermal stability, not easy to release gas. Natural mica powder is widely used in electrical appliances, welding rods, rubber, plastics, paper making, paint and other fields. Synthetic mica powder is mainly used in high-end electrical insulation materials, aviation, aerospace, national defense industry and other high-tech fields. Because synthetic mica powder needs to be produced through complex chemical processes, its production cost is usually higher than that of natural mica powder. Therefore, in the market, the price of synthetic mica powder is often higher than that of natural mica powder. However, with the continuous progress of production technology and the gradual emergence of scale effects, the price of synthetic mica powder is expected to gradually decrease.