This deal has ended.
Update: payment via Visa is required. Take a rare 10% off at best-of-breed online jeweler Blue Nile via coupon code VISAW36. Blue Nile is the largest online jeweler, having sold over 50,000 engagement rings. They buy diamonds through the same wholesalers that Tiffany's does, but can sell for 35% less. As always, there is free FedEx, no sales tax and a fully guaranteed 30-day return policy.