Jewellers....need some help (Wedding bands)

[beanbag]

I need to buy the wedding bands for me and my missus (to-be), and although we know we want platinum bands, we've stumbled across two types. Platinum 600 and 950.

I know the engagement ring I bought is platinum 950 since this is what the jeweller told me however what's the difference and can I tell?

If it makes any difference at all, I'm getting my ring brushed and hers will be a polished finish.

Ta,

BB