While we might not be throwing our wedding rings out with the weekly rubbish, as a society we are becoming more and more reliable on disposable materials. We don't buy things for keeps anymore, and some people even "upgrade" their engagements rings every few years (Victoria Beckham apparently has 14). If you're a conscious consumer, keep it vintage and make a home for one piece of beautiful jewellery that already exists in the world.
Top tip: Although you might want to start your search with nearby shops and antique markets, when you've determined exactly what you're looking for, you can expand your search the world over with reputable sellers on sites like Etsy or Ebay. Buying from abroad opens up new opportunities, especially if you like a certain style or stone that was prevalent in a certain part of the world.