The famous 4Cs of diamonds

The diamond, if properly cut, is a stone of exceptional beauty and brilliance whose main characteristic is the sparkle determined by the combination of 4 main factors, the famous 4 Cs:

Color

Cut

Clarity

Carat

The combination of these characteristics allows us to determine the selling price of a diamond.

Below is a short guide to understand how each of these impacts the classification and therefore how the price of diamonds is determined.

The Color (color)

Many people improperly call it the diamond's light and it is perhaps the most important characteristic, in some cases even appreciable to the naked eye and in a mounted diamond.

Generally speaking, in white diamonds, the whiter the diamond, the more valuable it is, so any color reflections (usually yellow) are considered defects. The exact opposite happens for fancy diamonds, where it is desirable for the color to be as marked and vivid as possible.

Color has a significant impact on the value of a diamond and contributes to determining its price. In fact, together with purity, it is the fundamental characteristic used in the famous Rapaport price list.

A D color diamond (beautiful white color, used in the finest jewelry) has an average price 70% higher than a I color stone with the same carat weight and clarity.

Determining the color grade of a diamond is therefore an important operation that is still carried out with traditional methods using reference stones called touchstones whose color is known and which are placed under a white daylight light that reproduces the diffused light of a sunny day. The touchstones are placed next to the diamond to be checked on special white cards and the color grade is determined by direct comparison.

Of course, the eye of the gemologist who assigns the color grade must be particularly trained and rested because even the slightest error, especially for high-carat diamonds, can mean tens of thousands of euros of difference on the final value. For this reason, color verification sessions do not last more than 3/4 hours in a row.

There are several diamond color grading scales, but in recent decades the GIA (Gemological Institute of America) scale has become the de facto reference standard and has been adopted by all other diamond grading laboratories.

The Cut

The cut of a diamond is an extremely important characteristic because it ultimately represents the ability of a stone to optimally reflect light and therefore determines its brilliance and shine.

The cut is therefore understood as the quality of positioning and proportioning of the various facets (as many as 57 in a round brilliant cut diamond) and of the girdle and should not be confused with the cut understood as the shape of a diamond which we will discuss later.

In a diamond, when cut properly, much of the light entering through the top facet (the table) is refracted twice at right angles and then exits again through the same facet, returning toward the observer, causing the diamond to sparkle or sparkle.

If the proportions of the diamond are not correct it essentially means that a certain amount of light is not reflected and therefore brilliance and brightness are lost.

The classic round brilliant cut has 57 facets, 33 of which are on the upper part (crown) and 25 on the lower part (pavilion). Sometimes there is also a 58th facet which is formed by the tip of the pavilion (in English culet) when this is not perfectly pointed, thus forming a small facet.

In a perfectly cut brilliant the pavilion should be pointed and not flat and optimum brilliance is achieved when the crown represents approximately one third of the total height of the stone.

The quality of a diamond's cut is therefore determined by a whole series of measurements of angles and positioning of facets, but for convenience all these complicated formulations are included in a synthetic and common judgment for the main certification laboratories in 5 different grades that go from Excellent to Poor passing through Very Good, Good and Fair.

The most well-known and widespread shape is the so-called "brilliant cut", that is the classic round cut with a pointed pavilion, but there are many other original and highly effective shapes. Here are some:

 

The best known cut is the round, also called brilliant, with 57 facets, a round shape and a pointed pavilion.

The other cut that we at DIAMANTIA adore is the heart-shaped cut, very original and suitable for unusual solitaires with excellent brilliance.

Purity (clarity)

 

 

The purity of a diamond is the other very important factor in determining its value. Completely pure diamonds, therefore free from imperfections of any kind when observed under a 10x lens or a microscope, are quite rare and therefore very valuable. These diamonds, called Internally Flawless, are generally intended for the investment diamond market, they are rarely mounted in jewelry.

Much more often, however, diamonds used in jewelry are not completely pure, but have some tiny imperfections inside them called inclusions and the diamond is all the more precious, the smaller these inclusions are. On the other hand, when the diamond is made up only of inclusions we speak of black diamonds.

It must be said that differences between stones with consecutive grades on the diamond clarity scale are very difficult to spot for non-experts and only a person with a trained eye and the help of a white solar light lamp and a magnifying glass (or microscope) can establish whether a diamond is a Vvs2 (Very very small inclusions) rather than a Vs1 (Very small inclusions).

At first glance, these two purity classes appear to be absolutely identical, even more so if the stones are already set in a mount, even though there is a certain difference in value.

For this reason, it is always advisable to purchase diamonds only from serious traders through official channels and, above all, it is essential that the diamond has an internationally known certification, therefore reliable. We will never tire of repeating that there are only a few certification institutes in the world capable of guaranteeing the maximum impartiality of judgment of a gem.

GIA - IGI - HRD - Diamond Clarity Scale Grade

• IF - completely pure under the microscope (The diamond is completely pure, therefore free from inclusions of any kind when observed under a microscope or under a magnifying glass at 10x magnification)
• VVS1 - Very Very Small Inclusions 1 - VVS1 clarity diamond with almost no inclusions
• VVS2 - Very Very Small Inclusions 2 - VVS2 clarity diamond with minimal inclusions
• VS1 - Very Small Inclusions 1 - The diamond has very few inclusions of minimal size that are difficult to detect under a 10X lens, mostly located outside the table.
• VS2 - Very Small Inclusions 2 - The diamond has very few inclusions of minimal size that are difficult to detect with a 10X lens, located in the center of the table.
• SI1 Small Inclusions 1 - The diamond has inclusions and/or characteristics that are difficult to observe with the naked eye by an inexperienced person
• SI2 Small Inclusions - The diamond contains inclusions and/or characteristics that are visible under a 10X loupe, sometimes even to the naked eye.
• I1 Piquè 1 - The diamond contains large inclusions that are clearly visible to the naked eye, the brilliance is very low, the diamond does not look good
• I2/I3 Piquè 2/Piquè3 - The diamond contains very visible inclusions that are easily visible even to the naked eye. The diamond has the appearance of a grain of salt and does not sparkle.

The Carat

 

The carat in reference to diamonds (and more generally to all precious stones) is the unit of measurement of the weight of the stone and is equivalent to a fifth of a gram (0.20 grams) and should not be confused with the carat intended as a measurement of the purity (also called title) of precious metals such as gold or platinum which is instead abbreviated to Kt.

On the contrary, the carat, intended as the weight of a gem, is abbreviated to ct. In a round brilliant cut stone there is a certain proportionality between the carat and the diameter that can be summarized by this weight/carat table, but the carat is not the size of a diamond but rather its weight.

As is well known, carat contributes significantly to the cost of a diamond, not only because the value increases with the increase in carat, but above all because the cost is proportional to the weight only within the same carat range. That is to say, for example, a single stone of one carat (1.00ct) has a value much higher than that of the sum of two stones of 0.50 carats even though the total weight in the two cases is always the same (i.e. one carat). This is because the stones in the example belong to two very distinct carat ranges, each with a different price per carat.

Finally, it is useful to know that the carat weight of diamonds is often expressed in carat points, where a carat point is one hundredth of a carat (0.01ct).

Fluorescence

Fluorescence is the natural characteristic of some diamonds whereby if the stone is hit by UV rays it instantly emits bluish radiation of varying intensity that is completely harmless to humans. It should be reiterated that this is a natural characteristic so there is nothing strange or suspicious if a diamond has a certain fluorescence.

In a diamond, the possible presence of fluorescence must be evaluated under two different aspects: Qualitative and commercial.

From a qualitative point of view, fluorescence, except in rare cases, has no effect on the beauty and clarity of the diamond which, observed in sunlight, appears like any other diamond without fluorescence. Even after mounting in a jewel there are no visible phenomena and the stone is beautiful and brilliant like any other. In a very small number of cases, fluorescence is accompanied by the so-called milky effect, that is, the diamond appears milky and not clear as it should. The most important gemological laboratories such as IGI, GIA or HRD report this occurrence in the certificate so that there are never any surprises for the buyer because the milky effect tends to depreciate the diamond. As mentioned, fluorescence can have various levels starting from None = none up to Very Strong = very strong and the only tangible effect of a stone with very high fluorescence is possibly that for which if we frequent a disco with UV lights then probably the diamond will appear colored blue.

From a commercial point of view, however, the presence of fluorescence should always be seen as an element that negatively affects the price, with varying degrees based on the intensity. In the sense that a diamond with Very slight or slight fluorescence (generally abbreviated as VSL and SL) will have a minimal difference in quotation, sometimes even zero compared to a diamond without fluorescence, while a diamond with very strong fluorescence will certainly have a more markedly reduced quotation.

If we have to establish a rule for an intelligent purchase of a solitaire stone, we can say that it would be preferable to avoid buying a diamond with strong or very strong fluorescence even if the price is lower, but if we really have to do it, let's at least check that the diamond has a clear and transparent appearance.