Heh, *I'm* the one who bought our wedding rings. I am pretty much allergic to most metals except for sterling silver. So of course the rings would be sterling siver. Then a friend of mine who has a small side business with jewelry had a catalog she let me look through, and I found some nice celtic knotwork rings that came in men's and women's sizes.
And I spent a whole $35 for each ring.

Funny story with that, I figured on getting 2 of each, so that when DH and I lost weight, we could have them cut down. Well, at a rpg gaming session, his ring somehow breaks at the weld, and his friends are joking that he has freedom for a little while, and I say "Don't worry honey, I have the other ring at home" and the guys are all saying "She bought a duplicate ring?!?!? You're doomed!!!"

Oh, and no engagement ring, and no diamond. If i had to have a stone, it would probably be a moonstone, like a ring I wear on another finger.