Blue Nile Sells Real Diamonds You can rest assured that all the diamonds we sell are real, and we offer the paperwork to confirm this. If you're purchasing diamond jewelry or loose diamonds from our online jewelry store or local jewelry showrooms, you can rest assured that you are purchasing genuine diamonds.

Blue Nile diamonds are absolutely legit. But because they cost less than diamonds at brick-and-mortar retailers, it's understandable how someone shopping for a diamond or jewelry piece might be skeptical. The price difference is all in the business model.

If you're serious about finding out whether your diamond is real or fake, you can put the stone through a fire test. Use a lighter to light the stone for approximately 30 seconds, before dropping it in cold water. If it's a real diamond, the stone will remain unharmed, but if it's fake, it will shatter to pieces.

Fancy vivid blue diamonds are among the rarest and most sought-after gemstones, which often translates into higher prices. As a general guideline, you can expect the price for a fancy vivid blue diamond to start at around $100,000 per carat, for smaller stones with moderate color intensity and clarity.