“If you liked it then you should of put a ring on it,” Beyoncé/Sasha Fierce/Queen Bey, 2008. Long before Queen Bey sang those immortal words (we can’t be held accountable if Single Ladies is stuck in your head for the rest of the day), the engagement ring was a chameleon, changing forms and floating in-an-out of popularity for years before it’s resurgence in the 20th century. And although we’ve come to know the classic engagement ring as a diamond, it wasn’t u