Diamond value

When buying a diamond, it is important to understand which components form the price of a diamond. First of all, you need to make sure that the diamond is natural, since only price list data applies to natural diamonds. In addition to natural, there are still artificially grown diamonds - “synthetic”, the market of which is not regulated.
The formation of a diamond’s value is also influenced by the main “4’С” evaluation characteristics - weight, color, clarity, cut - its shape, appearance and quality. In addition to these, the presence and intensity of luminescence, accompanying gemological reports to the stone, the type of market and the region in which the purchase and sale transaction is carried out, and additional terms of the transaction are important.

On the territory of the Russian Federation, the term “diamond” means only faceted natural diamond, which can subsequently be refined in color and / or purity.
To determine the value of loose diamonds, the Rapaport Price List, which is published weekly every Friday, serves as the main indicator of prices on the world market.
The Rapaport price list is available in two versions - for the standard round cut “Round” (57 brilliant cut diamonds) and for the diamond cut “Pear” shape (pear), applicable to all fancy cut shapes. Read more about the types of cut diamonds. At the same time, each form in its own weight range is characterized by its own conversion factor, determined from the data published in the journal “Rapaport”.
The price list reflects the level of high supply prices in retail in the New York region for loose diamonds of the “A3” cut quality according to the Rapaport classification (Very Good - according to the ISO and GIA classification), having confirmation of the declared quality characteristics in the form of a GIA gemological report. The price list itself plays the role of an index that reflects the average supply prices in a particular market segment. Depending on the quality of the cut, the state of the stones, the accompanying documents, the completeness, the region of the transaction and other conditions, either premiums or discounts are applied to the Rapaport price list. The usual level of mark-up discounts is in the range from +15 to -35%, but there are stones to which coefficients with a higher or lower value of the mark-up discount can be applied.

Let's consider in more detail how to work with the Rapaport price list. The table in the left columns shows the color characteristics of the diamonds, and the upper two rows indicate the intervals of the weight of the diamonds for which the table is presented, and the purity characteristics of the diamonds. In addition, for stones located in the upper mass range, the correction factor for the extra weight is given. The final price values ​​determined at the intersection of rows and columns in the table are given in hundreds of dollars per carat (Fig. 1).
The main tables are also given tables of discounts for luminescence, as well as tables of premiums for diamond weight (relative to the values ​​of 5.00-5.99 carats) in the range from 6.00 to 10.00 carats. In addition to the price lists, there is a reference table of discounts-allowances for round diamonds that reflects the real market value based on transactions in the Rapaport online trading network (Fig. 2).
It is more accurate to evaluate a diamond based on data from the RapNet trading network. In this service you can see both current offers and information on completed transactions, as well as familiarize yourself with additional conditions for the sale of a stone (the presence of a gemological report containing assessments of characteristics according to the international standard, cut parameters, luminescence, etc.).

There is a round brilliant cut diamond, "Round Brilliant cut", weighing 0.38 carats, accompanied by a GIA gemological report. The color characteristic is “H”, the purity characteristic is “VS2”, the cut characteristic is “Very Good”, the stone has bright blue luminescence.

Step 1. Using the Rapaport price list for the current time period, we determine the basic cost indicator according to the price list (offer price):

Fig 1. Finding a basic indicator of the cost of a diamond with the given characteristics according to the price list of Rapaport - 1700 $ / ct.

Step 2. Correction of the basic indicator of the value of a diamond in accordance with the adjustment for weight and quality of cut (+ 10% - + 20%), select + 15%.

Step 3. Using the application of discounts on the luminescence of diamonds for the current period of time, we determine the discount on the luminescence of our diamond:

Fig. 2. Determination of the discount on the luminescence of a diamond with specified characteristics according to the discount table Rapaport - (-2% - -3%), we accept -2.5%.

Step 4. Using the RapNet application for the current period of time, we determine the regular trading discount for our diamond:

Fig. 3. Definition of a regular diamond trade discount with specified characteristics according to the RapNet discount table - -28%.

Step 5. Determining the average market value of a diamond with specified characteristics on the basis of a basic cost indicator in accordance with the Rapaport price list:
(Baseline + adjustment factor - luminescence discount - regular trading discount) x Carat weight = (1700+ 15% - 2.5% - 28%) x 0.38% = $ 521.52 per stone.

It should be remembered that the average market value may significantly differ from the real diamond offer prices, depending on the conditions of sale and purchase.

In addition to Rapoport, there are other professional publications that offer a review of diamond prices, but with their own specific audience. Thus, The Palmieri’s Market Monitor, published by the Gem Certification & Assurance Lab, is aimed at professional appraisers in the United States and reflects the position of insurance valuation in the United States of America.
The Gem Guide is focused on the jewelry market in general and the diamond market in particular (in the US region). This publication provides a wider range of basic shapes and cuts of diamonds, the prices of diamonds of extraordinary and fancy colors, as well as the prices of refined diamonds in color and clarity. However, the frequency of this publication is quarterly, and the representativeness of the sample is much lower than in the Rapaport network.
There are other reviews, for example, focusing on other segments of the retail sales market, but the Rapaport information network is the most authoritative reference and information source.

On the territory of the Russian Federation, to calculate the normative value of a diamond, which is used to determine the tax rate, insurance assessment, liquidation and other types of value used for accounting purposes, the price list of estimated prices for diamonds is used, which is not a periodical, but a normative document issued in accordance with decision of the Ministry of Finance of the Russian Federation.