I'm Jewish, and Jewish tradition holds that a wedding ring must be plain metal (gold/silver/platinum/whatever) without gems, so that the value of the ring cannot be misrepresented. I prefer white gold, my husband prefers yellow gold, so our wedding rings (which match) are yellow gold with a white gold inlaid design.
My engagement ring is a classic Tiffany-cut diamond in a platinum band. It's relatively small, but it looks right on me since I have long narrow fingers. A few people told me I could have it re-set as a side stone in a 10th or 20th anniversary band

but you know what... it's my engagement ring the way it is now. Mr. aephi alum will just have to buy me a really nice pair of earrings for our anniversary.