Before a diamond purchase you should ensure that you buy a diamond with certification. Diamond Certification is a document you receive from labs that describe a diamond in all its characteristics (color, cut, size, clarity) using a loupe or microscope. If you’re buying online, choose gems with the GIA or AGS certification — the most consistent lab available.
But one of the problems of diamond grading is that it is subjective, because there is no central organization that defines colors and clarities in one way. Some labs are looser in rating Color, while others are looser with grading Clarity. Different labs can give the same diamonds different characteristics what can lead to purchasing a diamond worth much less than its certificate says.
It’s important to find a reliable and trustworthy organization to heavily evaluate price of a diamond. The ideal pricing should be based on actual quality, light performance and cut of the diamond. To make sure that the price is fair, ask several experts.
But keep in mind that you buy a diamond and the main point is if you personally find it attractive.