Micas are used to add sheen.
Due to mica's natural sheen and luster, mica is the perfect choice for cosmetics and other beauty aids. It is very safe to use on sensitive skin. Mica is non-carcinogenic, non-toxic and totally inert and can be used for human applications.
Mica has many beneficial attributes for use in cosmetics: high UV stability, low abrasiveness, excellent lubricity, good skin adhesion, and good resistance to heat, weather, and chemicals. A major sales point for the use of mica in cosmetics is its ability to block UV radiation and thereby prevent skin cancer.