Silk Mica; Mica Powder Plain
Silk Mica is a relatively large particle mica (averaging 50 microns) which contains no additional whitening, such as titanium dioxide.
It is similar to our other uncolored mica, Sericite, except that it is more silky, whiter, and somewhat more expensive.
Silk mica is recommended as a filler/extender in loose mineral eyeshadow and face powder at a concentration of 10 - 40% because it offers up a soft, smooth texture and it is "mattifying".
For the same reasons, it is also a good choice for cream and pressed powder.