What are those rings called that are like half rings and are worn so there's a gap on the top?

[MrsMeow]

They're like a full ring underneath but then the two sides of the circle don't join so the top of the finger is uncovered.

Does anyone know what I mean? I can't even explain it well enough to google!

Torc?

Ooh that's definitely the style! The ones I've seen in the shops are less fancy than those though and have skulls etc on them.

Thanks!