THE 4C OF THE DIAMOND
To ensure proper certification of the diamond, there are international rules that allow an objective assessment in every part of the world.
Between the 40s and 50s the G.I.A. (Gemological Institute of America) developed the International Diamond Grading System. Thus giving birth to the evaluation system universally known as “4C”, as the acronym of the initials of the four fundamental parameters for the evaluation of a diamond:
Of all the evaluation parameters, the cuttin proportion is the most important.
When the proportions are perfect, all the light received from the stone is reflected from the table or from the facets of the crown, in fact the intent is to evaluate the refractive capacity, the term CUT refers not to the shape of the diamond, but to the quality of the cut .
If the pavilion is too high, or rather shallow, the light passes through the facets of the pavilion itself and is lost without making the stone shine.
EVALUATION OF THE CUT:
The only stones that can be classified as cut stones are those with 0.25 carats upwards
The fundamental elements for the evaluation of the cut of a diamond are:
– Table diameter percentage: the proportion of the width of the table relative to the diameter of the shape of the brilliant cut.
– Crown height percentage: the proportion of crown height compared to
diameter of the brilliant cut shape.
– Pavillon depth percentage: the proportion of the depth of the pavilion compared
to the diameter of the shape of the brilliant cut.
If it is true that the perfect stone is colorless, it is also true that there are naturally colored diamonds often appreciated more than the white ones thanks to this characteristic, where the color is so intense that it becomes a quality.
The color of the diamonds is evaluated by illuminating the stone from the north and on the white paper, all this to avoid distortion by sources of artificial natural light.
The coloring is a phenomenon due to the presence (in small percentages) of chemicals that give the stone pleasant shades of yellow, blue, green and pink.
The only valid method to determine the exact color of the diamond is to compare it with another that has been classified as a touchstone.
A diamond formed over 900,000 years.
In such a long period of time inside the crystal are incorporated internal microinclusions and external stains whose classification helps to determine the value of the gem.
It therefore evaluates how many imperfections the stone contains and its total characteristics: external and internal.
The weight of the precious stones is determined in carats.
One carat corresponds to 0.20 grams; it takes five stones of 1 ct. to equal the weight of 1 gram. The carat, in turn, is divided into 100 parts: 1 cent of carat equals 1 point.
It seems that the adoption of the carat, as a unit of measurement, dates back to 1200 and is due to Marco Polo, which, in the need to standardize, in the various markets with which it came into contact, a unit of equal weight for all, he used the seeds of the carob tree (carat in Arabic).
The seeds of the carob tree have the characteristic of always having the same weight, whether it is the gigantic carob trees of the savannah or the tiny fruits of the areas with a temperate climate.
Now we use different methods of course, using electronic microbalances that can measure weight up to five digits after the decimal point.
Monitoring the weight throughout the process of processing a diamond is certainly a fundamental safety operation.
In 1970, for the first time, it became necessary to have diamonds that enjoyed international certification. This is in favor of a nascent investment market in diamonds and with a recognition of their value that was universally accepted. In short, we gave the shared certification parameters and the three large International Certification Institutes arose:
- GEMMOLOGICAL INSTITUTE of AMERICA (GIA)
- HOGE RAAD VOOR DIAMANT - ANTWERPEN (HRD)
- INTERNATIONAL GEMMOLOGICAL INSTITUTE - ANTWERPEN (IGI)
Since then the certificates issued by the aforementioned Institutes perform the function of international recognition that, in close connection with the RAPAPORT price list, allows an immediate and univocal diamond value assignment all over the world.
RAPAPORT – DIAMOND REPORT
The famous “RAPAPORT”, official list of diamonds, is published weekly in New York and has a planetary value.
Rapaport prices are expressed in US Dollars. In the Rapaport price list we consider the weight, the color and the purity and not the cut, an important element for the evaluation of the single stone. This price list is therefore to be considered “reference”.
It is the only price list that guarantees a serious quotation, free from manipulations, and under the control of Diamond Trading Company.
DTC, in the cartel with the Russian ALROSA, with which it shares the world diamond market, manages the crude to be supplied to the market by calibrating the quantities according to market demand and guaranteeing the annual increase in the value of the diamond to make it the most safe and attractive among all forms of investment.
The Kimberley Process is a joint agreement between the governments of the world’s major countries and the diamond-producing multinationals, which guarantees, under the aegis of the UN, that profits from the diamond trade are not used to finance civil wars.
The agreement also obliges participating countries to strictly control the import and export of rough diamonds.
The Kimberley Process was stipulated in May 2000, during a conference in Kimberley, South Africa, to try to solve the problematic link between the production of diamonds and war conflicts.
The agreement takes its name from Kimberlite, the rock from which the diamonds are mined and from the city of Kimberley, where the first deposits in South Africa were discovered.
In 2002, 37 States signed an agreement for the activation of a certification system in the circulation of rough diamonds in Interlaken.
The requirements that must be met to be able to join the certification scheme are basically three:
– Diamonds can not be used to finance rebel groups or other organizations that aim to overthrow the government recognized by the United Nations.
– Each diamond exported must be accompanied by a certificate that proves compliance with the Kimberley Process scheme.
– No diamond can be imported from, or exported to, a country that is not part of the Kimberley Process.
A certificate of origin certifies the whole path of the stones, guarantees the origin and all the steps, from the rough to the cut diamond.