Why add mica in cosmetics

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For Asian women, to be naturally white, it is more important to have a proper gloss: if the facial gloss is too little, the skin will look dry and malnourished; but too much gloss is too greasy, and oily skin is more likely to appear on dull skin.

　　In cosmetics, how to make the face shiny? One is to add some oil, but may affect the skin feeling, the product feels greasy after use. Another is to add mica to skin care products and make-up products.

　　Why mica can shine? Here’s a little bit about it.

　　The first is the flaky structure of mica: mica is a rock-forming mineral. Mica used in cosmetics usually has a flaky structure, as shown in the figure. If the sheet structure can cover the pitted skin surface with a layer, the light can form a mirror reflection, rather than a diffuse reflection without a fixed direction, so that the light reflected by the mirror can shine.

　　Secondly, the light irradiated on the mica has a high reflection and a small transmittance so that the light does not pass through the mica (not like glass), but reflects on the surface of the mica.

　　The above two characteristics of mica are summarized as follows:

　　Shine’s definition itself is a comparison between specular reflection and diffuse reflection. If the light passes through the material, or is diffused, it will not be able to form a mirror reflection, forming a gloss.

　　The characteristics and structure of mica can form reflection rather than transmission. On the other hand, the sheet structure determines the mirror reflection that mica can perform (imagine the numerous small mica mirrors on your face), so that mica can form a good gloss.

　　Mica is widely used in the cosmetics industry as pearlescent agent to increase the brightness of products, or to brighten skin color on the skin surface, so that the skin has a better gloss.