Can someone tell what is the difference between the Ideal cut in diamonds at Blue Nile versus Tiffany and co?

No 2 diamonds are alike because each diamond has its own set of blemishes and imperfections. Having said that, there are a total of 5 factors that you want to consider before comparing diamonds.

Firstly, who certified the diamond.
1. GIA
2. or AGS

If they have both been certified by the same agency, then a general comparison is possible. If, however, they are from varying agencies, there may or may not be problems.Tiffany Bracelets

Then, you need to look at the 4C's. I have provided a link below to the Blue Nile page that gives a great introduction into what to look for in a diamond.Tiffany Co Earrings 

Therefore, if they have been certified by the same organization, and they have the same cut, color, clarity, shape and weight, then the only difference would be the setting.

Where can you buy a copy of Tiffany Co Necklaces besides new york?

I have bought some copies of Tiffany and co necklacesat cannel street in new york but i am going away and i want to know where else i could get some good ones. please help!

I hate to be a downer, but I want to truly discourage you from purchasing fakes when it comes to fashion. Imitations of popular brand name items such as  Tiffany Jewellery and Louis Vuitton bags are so easy to find and in huge quantities...why? because they are mass produced in poverty-stricken communities with small children and near-death elderly persons operating the machinery. YES, it DOES happen, it IS happening, and it's not only unethical, but unoriginal.

The workmanship on these items is of poor quality, thus the item will wear out quickly. There is a reason the real thing is so expensive. It is of a much better quality, and there are fewer produced; therefore, you become the owner of something truly special. Please save up the money and go for the real thing. Support the true artists behind the design, not the Communist Chinese. Plus, having to save for it will make it that much more special to you, and you can pass it down through many generations after you.