True mica powder and False mica powder? How to identify it?

Actually, it's easy to identify mica powder. There are three methods as follows:

1,We often receive the reaction from customers that the whiteness of mica powder is 90 or so. Under normal circumstances, the whiteness of mica powder is generally not high, only about 75%. If it's doped with other fillers such as calcium carbonate, talc and so on, whiteness will be greatly improved.
2,Mica powder is a sheet structure. Taking a beaker, adding 100ml  pure water and stirring with a glass rod, you can see the suspension of mica powder is very good. Other fillers' suspension including transparent powder, talc and calcium carbonate is belower than mica powder.
3,Painting a little on the wrist, there is a little pearl effect. MIca powder is widely used in cosmetics, coatings, plastics and rubber. If the purchase of mica powder's pearl effect is poor or without any pearlescent effect, this should be noted.