Diamonds are not that rare. They're durable, so it's not like an old diamond is going to break or something. So, there should be plenty of diamonds for everyone who wants one. Rings made in the 1920s and up probably have some sort of diamond in it, and if you don't like the ring, keep the gem and craft a new ring around it. I prefer more rare stones, such as a padparadscha sapphire, or Alexandrite. I prefer to give my woman a gemstone as rare as she is, and as colorful as she is, not something which has virtually no color, and is definitely not rare.