Santa Monica/LA - Any "must see" jewelry stores?

[maccers]

In November, SO and I will be in Santa Monica briefly, we have one 'free' day to spend as we please (a Friday). SO is a-okay if we spend part of that day checking out a few jewelry stores - does anyone have some highly recommended stores we should visit?

I'd also like to check out a store that carries Niessing rings - I love the feat of engineering and beautiful architectural look of them. As far as I can tell, only two stores in LA carry Niessing: Servis & Taylor (which is closer to Santa Monica) and Oscar's Design.

Has anyone been to either of these stores? What are your thoughts?

Thank you in advance!