The Rapaport diamond price list separates the different sizes, colours and clarities of diamonds and arranges these factors into price categories. The problem arising in using the Rapaport list is the subjective nature of diamond grading. Some speak about a Rapaport price and do not consider the price variation from a cut perspective. Some speak about a Rapaport price and do not consider the variation of grading standards from one laboratory to another. Some speak of a general discount that is below the Rapaport list that does not take into consideration the premiums the market demands for certain size categories.
The truth is that a Rapaport list price is very subjective and can be used to the advantage of a buyer or seller. The same stone could be sold by one dealer at 10% below Rapaport using one laboratory certificate and 30% below Rapaport using another certificate.
The price of a diamond does not depend on the Rapaport list. The price of a diamond depends upon the accuracy of the grading system. The dealer who buys a diamond with weak grading, at deep discounts below the Rapaport price list, is getting and selling exactly what he pays for. The dealer who is selling with a more stringent set of standards delivers a product that on the surface looks more expensive but upon further examination may have a much better value than the diamond with a pushed grade. The Rapaport list, when misused, allows for the comparison of apples and oranges when they cannot be compared.
The informed buyer needs to understand the product, the pricing and the grading standards. A Rapaport discount and a certificate are no guarantee of value.