Features and information on Diamonds

The 4Cs of diamonds

Classification is a fairly straightforward concept when it comes to diamonds and the term is known by even the most common consumer when they begin to show some interest in a stone.

In some ways this awareness, which can be more or less superficial, is justified: from the moment in which any diamond enters the outside world, until it passes to an end consumer and throughout its life, therefore perennially, it is classified!

Once a stone is formally classified according to the international criteria of gemological analysis, it has acquired a “certification”.

International classification standards for cut diamonds were introduced in 1953 by the GIA (Gemological Institute of America) and are: Cut, Clarity, Colour and Carat (weight).

Cut

An evaluation is based on parameters such as proportions, polish and symmetry, each judged according to grades ranging from the highest “Triple Excellent” (3EX), to “Excellent” and through to the lowest “Poor”.

The cut is the only variable that depends solely on man’s skill and can have consequences on the quality and quantity of a stone’s brilliance, a very important condition for a diamond if you take into account that its beauty largely depends on the amount of light it reflects.

Clarity

The parameter is related to the presence or absence of inclusions or impurities in a stone that are usually not visible to the naked eye.

The number, position and size of these impurities determines the degree of purity that is expressed on a scale of 11 degrees (FL – IF – VVS1 – VVS2 – VS1 – VS2 – SI1 – SI2 – I1 – I2 – I3), in which FL indicates the absence of inclusions, up to I3, which indicates inclusions that are often visible even to the naked eye.

All too often, the “purity” parameter has been considered decisive when classifying a diamond; however, diamonds have to be judged on the basis of all their characteristics:

Firstly, because the purity of a stone, even one with inclusions, must be evaluated based on how much an inclusion worsens the transmission of light;
Secondly, because certain particularly unusual inclusions may actually determine the peculiarity or rarity of a stone;
Thirdly, because the most interesting and dynamic markets are those that consider beauty and brilliance as a whole;
Fourthly, because diamonds with the highest degree of purity, i.e. “pure”, are very rare and represent a very small segment of the market.

Color

According to GIA criteria, it must be graded on a scale
that ranges from D = colourless to Z = yellow or brown.

Unfortunately, colour is very often used in isolation to determine the value of a diamond. Nothing could be more wrong because, as mentioned above, the rule when classifying a diamond is that “the whole is more than the sum of the individual parts”, i.e. its characteristics should be evaluated in their entirety. Secondly, because the colour greatly affects the cut: an excellently cut diamond will undoubtedly take on a qualitatively and aesthetically better colour!

Diamonds graded from J to Z range from a slightly tinted, very light yellow through to light yellow, the colour of less valuable diamonds.

Carat

Like the other elements considered, classification is based on the concept of rarity: the rarer a diamond is, the higher its value.

But beware!
While diamonds from 10.00 Ct (not Kt, which is the carat used in jewellery for gold) upwards are hard to find on the market, and therefore rare and of “value”, those ranging from 0.50-0.75-1.00-1.50-2.00 Ct, although not rare and of lower value, are also in high demand on the market and, for example, are excellent for those wishing to invest.

A carat equals one fifth of a gramme:
1 carat = 0.2 grammes.
0.5 carats = 0.1 grammes.
0.25 carats = 0.05 grammes.
0.125 carats = 0.025 grammes.

Consequently:
1 gramme = 5 carats.
0.5 grammes = 2.5 carats.
0.1 grammes = 0.5 carats.
0.05 grammes = 0.25 carats.
0.025 grammes = 0.125 carats.

The 4Cs are supplemented by an additional 2 parameters

Fluorescence

Fluorescence indicates the intensity of light emitted by the diamond when exposed to ultraviolet rays. The brightness tends to be a blue/azure colour.
The degree of fluorescence depends upon the intensity of the light emitted:
None – Faint – Medium – Strong – Very Strong.
The less fluorescence in a diamond, the higher its quality.

Certificate

All the information related to the certified stone from accredited gemological institutes (GIA HRD IGI INTERNATIONAL).

Certifications do not provide an estimate of the monetary value of a stone, but it is very important for the gemological certificate of a diamond to be internationally recognised to avoid problems or devaluations should the stone be put on the market at a future date.