[randomswede]

In Sweden, it is more customary (at least for mixed-gender couples) to buy matching gold bands for the engagement, then a fancy wedding band for the female spouse (and optionally another plain gold band for the male). They typically have the names and dates of the engagement/wedding engraved on the inside, as well.

Both times I got engaged (only got married once, though), I brought my partner to the jewellery store to pick out rings we both liked, as it would be something we'd be wearing for a non-determined time and I'd say that being happy with that trumps the whole "propose with a ring out of nowhere in public".