There is a mineral makeup advertised that it is healthy enough to sleep in.  You told me once that I should never go to bed without cleaning off makeup and applying treatments. Do you think it is okay to sleep in mineral makeup? 

In a word, no.  I once read that every night you go to sleep in your makeup, you add three days to your facial age.   Firstly, if you are sleeping in makeup, chances are that this is the same makeup that was applied early in the day, fourteen to sixteen hours earlier.  The nighttime is when your skin has an unequalled opportunity to spend hours cleaned of all of the environmental dust and accumulated impurities that lead to clogged pores and the subsequent blemishes, blackheads, and lines.  Clean skin that is allowed to absorb healing and anti-aging ingredients over the course of sleep will experience fewer enlarged pores and wrinkling.  Sleep is a time of renewal, and this includes cellular metabolism that enhances the regeneration of surface cells that puts the glow into your complexion.

Now, human nature being what it is, you may do it anyway.  If you must, clean your skin, use your toner and treatments as usual and apply a very light dusting of a finishing powder.  Avoid wearing mascara, as it will cause your lashes to break off (for this same reason, do not constantly use waterproof mascara).  The only makeup that I would consider acceptable for night wear is a little color added to your eyebrows.  Everyone looks better with eyebrows.

All in all, the best thing you can do for your skin is to keep it healthy, clear, and free of blemishes and discoloration so that you will feel absolutely beautiful just the way you are.