What does the Qu'ran say about hijab, exactly?

thats opposite with what is happening with me, my mum used to be religious when i was like 12 and i wanted to wear the hijab but my dad didnt let me, now my mum isnt religious and i started to wear hijab yesterday and shes upset about that. i wish i was in your situation, it sucks to have your parents (who you are meant to respect above all other people) against what you should do islamically.