Question

Proverb expansion of all that glitters is not gold

Answer 1

that is for example friends not everyone some
if they are beautiful and if we become friends some ways or the other if their heart is black they cheat us.
next example that is knife is very shiny and if we play with it and it cuts our hands if we doesn't use it properly

Answer 2

It means that outward impressions are deceiving......This proverb is used in the merchant of Venice. It basically means don’t judge a book by its cover