What kind of cool earrings do I get for a 13 year old girl?

My oldest grand daughter will be 13 on Friday. She’s had her ears pierced since she was 2. Mom gave the go-ahead for her to get an upper ear piercing for her birthday. I want to get a cool set of stud earrings for her, but have no idea what.

She’s kind of into the 70’s, because her dad is a music man and mostly sings 70’s songs.

She’s cool and groovy and beautiful.

Any ideas?