I'm not sure how to approach this question.
Something from Steven Universe? A show I haven't watched and... Don't really know anything about.
Are we talking like... Magic amulets? Or just normal gemstones? I'm gonna assume we're just talking normal jewlery.
I'd probably say Saphire or Amythest, I think both of them are beautiful.
I... Don't know how to answer the second one, though.