The mica variety that does not contain iron is colorless in flakes, and the higher the iron content, the darker the color, and the more polychromatic and absorbable it is. According to the different chemical composition and optical characteristics, mica group minerals can be divided into Muscovite subgroup, biotite-phlogopite subgroup and lemica subgroup. The common mica are biotite, phlogopite, Muscovite and so on.

5. Coloring For edible mica powder, safe food-grade colorants may be added during this process to achieve the desired hues without compromising safety.

Natural mica powder and synthetic mica powder have differences in production methods, heat resistance and color transparency. As the name suggests, natural mica powder is made from natural mica ore after processing, retaining the original characteristics and composition of the ore. Its main components are SiO2 (about 49%) and Al2O3 (about 30%), while also containing K2O+Na2O (9%-11%) and so on. The synthetic mica powder (such as fluoroglogopicite powder), is the use of a variety of raw materials through high temperature reaction and other chemical methods synthetic, its composition and characteristics can be adjusted and optimized according to the need, the chemical formula is KMg3(AlSi3O10)F2, belongs to the monoclinic crystal system, is a typical layered silicate, relatively single and pure composition. The heat resistance of natural mica powder is generally 500-600℃, and some types, such as phlogopite, can reach 800℃. The heat resistance of synthetic mica powder is more excellent, and it can withstand high temperatures above 1200℃, and the melting point or crystallization temperature is about 1375±5. The transparency of natural mica powder is relatively low, and the color is diverse, including black, yellow, white, gray, green, brown and other colors, and may vary due to different ore types and processing methods. The color of synthetic mica powder is relatively single, usually colorless transparent or white, high whiteness, good optical performance, and high transmittance from ultraviolet to infrared band.

Mica is a very common rock-forming mineral, widely distributed in crystalline rocks. Its general chemical formula can be expressed as:

For example, the safe operation of high-speed rail cannot be separated from the escort of mica products.