porous

Q: I want to ask a question about cosmetic ingredients mica and stearate acid which is used in face powders and blusher is it halal to use it? I read that mica is a kind of silicate or silicone which sticks to your hair and will not come out. It is not recommended because you cannot do wudhu. 

Q: I have a hair dye, but I don't know whether the hair dye is porous or not. Please tell me how to know whether a hair dye is porous or not?

Q: Is wudhu permissible with nail gel on and how can a person know if water reaches to the nail with nail gel on?

Q: Can I perform Salaah if I have a little spray on my nail?