The diamonds are minerals made of crystallized carbon, for particular geothermal conditions, millions of years ago in the bowels of the earth. A very high pressure, at about 150-200 km of depth, and a temperature of over 1200 degrees allowed the carbon to crystallize in diamond. Thanks to the volcanic eruptions, the rough crystals have reached the earth’s surface and, to date, represent the hardest ever raw material existing in nature. Adamas, the Greek word from which diamond is derived, means really hard.
HOW MUCH IS A DIAMOND?
The quality and value of a diamond are classified according to four criteria (also called the 4 C of the diamonds, from the English words Carat, Cut, Clarity and Color):
1 carat diamonds corresponds to a fifth of a gram (0.2 g) and is the unit of weight with which a diamond is measured. A 1 carat diamond weighs 100 points. The abbreviation is Ct.
The cutting of diamonds is evaluated according to 4 values :
- Excellent : when the diamonds optimally reflect the light, determining its brilliance. These diamonds are quite rare.
- Excellent : even the diamonds of this category have a high degree of cut and better reflect the light.
- Good : the diamonds of this category are a bit ‘less bright and vivid, but they are of good quality.
- Discreet : In this case, the diamonds reflect less light and are less bright.
Purity of the diamonds
The scale of purity of diamant the counts six main values, from FL-IF up to I2-I3 and which takes into account the clarity of the diamond inside and on the surface, as well as the presence or absence of any visible stains with the magnifying glass and / or the naked eye.
Color of diamonds
The color of colorless diamonds is evaluated with the letters of the alphabet from D to J , considering the presence or absence of a white or yellow tint. The greater the transparency, the greater the value : those from D to F are rarer, and almost always used for fine jewelry. From G to J the color is increasing and from K to Z we talk about colored diamonds, that is light yellow.
The blacks diamonds nature are classified as precious gems; unlike most diamonds, they are completely opaque. Stones of extraordinary beauty, are considered very precious, even if cheaper than other colored diamonds.
The black diamond is a stone with a non-univocal symbolism: while in some countries, as in India, it is not well seen, in Italy it is considered the stone of reconciliation.
Let’s see the characteristics of the black diamond according to the 4C criteria.
Carat – Like diamonds and other precious stones, black diamond is measured with carat. Those naturally extracted are expensive but still cheaper than those of another color.
Cutting – Naturally extracted black diamonds seem very rough and must be shaped by a process called shearing or polishing.
Clarity – It is not a particularly indicative criterion in the case of black diamonds, because clarity indicates the number of defects or inclusions present in the diamonds and black diamonds do not refract light as much as other diamonds.
Color – The color of black diamonds is evaluated according to the criterion of intensity. The color is given by the graphite that was formed in the crystalline structure during the formation of the diamond.
THE DIAMOND CERTIFICATE
As already pointed out, the value of a diamond is based on the combination of the “4C of the diamond”: color, clarity, cut and carat. These internal and external properties are evaluated by diamond experts and described in a document called a diamond certificate, which officially demonstrates the quality and value of the stone or jewel in which it is inserted.
GIA DIAMOND CERTIFICATE
The GIA (Gemological Institute of America) is a non-profit organization in the field of gemology and is the most recognized and authoritative certification organization of diamonds in the world.