Micas are very important and very fun colors to work with. Their color ranges way beyond the rainbow, and mixing creates even more unique and beautiful shades. Micas come in different particle sizes. The ones that are smaller than 20 microns give a satiny appearance while large micas with up to 150 microns provide a sparkle effect. Untreated micas are transparent and are thus coated with iron oxide pigments (black, red, yellow) and titanium dioxide to create silver-white but also gold, copper and bronze shades. Others are coated with an additional layer of colored pigment including carmine, ferric ferrocyanide, D&C reds, chromium oxide and aluminum oxide. This combination results in a brilliant color effect.