If you’re like me, you like a good shimmer eyeshadow or shiny highlighter. But have you ever wondered exactly what gives your makeup that shine? In many cosmetics, even nail polish, you’ll find mica in the ingredients list. Mica is a group of silicate minerals with the most common being Muscovite.
Muscovite is a the most common mineral in the mica family with the chemical formula KAl2(AlSi3O10)(F,OH)2, or (KF)2(Al2O3)3(SiO2)6(H2O)
Mica has a couple unique properties that make it highly useful in industry. It has nearly perfect basal cleavage, which means that mica can only be cleaved in one plane. This allows mica to be peeled into very thin sheets that are incredibly smooth.
The structure of mica causes it to have nearly perfect basal cleavage, allowing it to be peeled into thin sheets.
Mica also has reflective properties that it can retain even when ground. Mica flakes can allow a pigment, like eyeshadow, to sparkle. Additionally, to achieve a metal pearl sheen, mica can be coated with another mineral, often titanium dioxide (TiO2). The thickness of the titanium dioxide layer can change the iridescent qualities of the color. Titanium dioxide is often used because its high refractive index allows it to reflect light.
If you look at the ingredients for many products, especially shimmer or metallic products, you’ll find they either contain mica or state that they may contain ± mica, titanium dioxide (Cl 77891).
Polybutene, Tri-Isodecyl, Trimellitate, Ppg-3, Benzyl Ether Myristate, Diisostearyl Malate, Mica, Calcium Aluminum Borosilicate (Calcium Sodium Borosilicate), Calcium Sodium Borosilicate, Silica, Polyglyceryl-3 Diisostearate, Glyceryl Behenate/Eicosadioate Pentaerythrityl Tetraisostearate, Fragrance, Disteardimonium Hectorite, Propylene Carbonate, Benzyl Alcohol.
The ingredients for Huda Beauty Lip Strobe, a shimmery gloss, contain mica
Isododecane, Synthetic Wax, Hydrogenated Polydicyclopentadiene, Calcium Sodium Borosilicate, Peg/Ppg-18/18 Dimethicone, Polybutene, Glyceryl Tribehenate/Isostearate/Eicosandioate, Mica, Silica, Nylon-12, Polyethylene, Perfluorononyl Dimethicone, Synthetic Beexwax, Polyglyceryl-4 Diisostearate/Polyhydroxystearate/Sebacate, Pentaerythrityl Tetra-Di-T-Butyl Hydroxycinnamate, Copernicia Cerifera (Carnauba) Wax, Tin Oxide, May Contain: (+/-) Titanium Dioxide (Ci 77891), Bronze Powder (Ci 77400), Aluminum Powder (Ci 77000).
The ingredients for Anastasia Beverly Hills Metallic Luster Liner contain mica and may contain titanium dioxide.
Dimethicone, Mica, Isododecane, Synthetic Fluorphlogopite, Diisostearyl Malate, Polyethylene, Calcium Sodium Borosilicate, Caprylic/Capric Triglyceride, Silica, Phenoxyethanol, Cetyl Dimethicone, Talc, Water, Tin Oxide, Carmine (CI 75470), Iron Oxides (CI 77491), Bismuth Oxychloride (CI 77163), Titanium Dioxide (CI 77891)
The shade Rosé all Day from the Too Faced Glitter Bomb palette contains both mica and titanium dioxide.
Mica is used across the board in the cosmetics industry. So the next time you find that perfect glitter eyeshadow or a beautiful metallic liquid lipstick, you can probably thank mica.