Most glitter is made out of a combination of aluminum and plastic. Because it is not possible to separate these during recycling, they must be discarded as waste. Glitter is considered a contaminant in the recycling system.... And it gets everywhere! 

Glitter is very messy, spreads easily, and is hard to clean up. It is a kind of microplastic that is dangerous to small sea life when it gets into the waterways. Avoid it as much as possible and definitely keep it out of the recycling bin!