Each diamond has certain distinctive characteristics: the so-called 4Cs: cut, clarity, color, carat which are the globally accepted standards for evaluating the quality of a diamond.
The cut is determined by the way in which the facets of a diamond interact with the light.
If the cut reflects very precise measurements and proportions, the optical characteristics of the diamond are enhanced to the maximum, ensuring an almost total reflection of light from the inside of the stone towards the outside.
In addition to the proportions, the success of a brilliant cut is also determined by the asymmetry of the cut, which can be very good (VG), good (G) or medium (Medium).
A further element considered in evaluating the accuracy of the cut is polishing. During the cutting operations the veneers are polished so that all traces of the machining are eliminated.
However, it is possible that some surface lines remain on the veneers, called polishing traces.
The finishing and polishing do not affect the purity of the stone.
The set of proportions, symmetry and polishing define the so-called “finish”.
The cut can also refer to the shape that the diamond can take. The type of cut can vary the price of the diamond, the most expensive is the round cut while the cheapest is the radiant cut.
Why is diamond cut so important?
If a diamond is badly cut, it will appear dull even if it has a high color and degree of clarity. If a diamond is cut well, it will reflect and refract light for maximum brightness and brilliance.
What affects the quality of the diamond cut?
The “cut” is the only one of the 4Cs that depends on human hands. Two diamonds can have the same purity, color and carat weight: but the cut is what determines whether or not one is superior to the other. In other words, the cut is responsible for the quality and degree of brilliance of a diamond. There are three factors that determine the cut of a diamond:
Cutting precision: how dimensions and angles refer to the different parts of the stone
How precisely the various facets of a diamond line up and intersect
The details and positioning of the facets and the external finish of the diamond
The industry’s highest cut grade, triple excellent, is awarded to a diamond with an “excellent” score in terms of cut accuracy, symmetry and polish.
Purity is a measure of the rarity of the stone.
In diamond, the more the stone is free of inclusions, the higher its value.
An inclusion can be a crystal “housed” within the gem, a crack or other.
The factors that influence the expert’s final decision are:
- the number of inclusions,
- their grandeur,
- the position that they have inside the stone (one inclusion affects more on the table than one on the crown or belt),
- contrast (some inclusions, such as feathers, are very visible in some positions, while in others they can be practically invisible; crystals on the other hand usually have the same contrast in all positions);
- the color (we find black, white and/or rarely red inclusions).
DIAMOND GRADING SCALE:
- IF: “internally flawless”, which means there is no inclusion.
- VVS1 – VVS2: “very very slightly included, which means that the inclusions are only visible with the use of a microscope, with a 20x – 30x magnification.
- VS1 – VS2: “very slightly included”, which means that the inclusions are only visible with the microscope or the “jeweller’s lens”, with a 10x magnification.
- SI1 – SI2: “slightly included”, which means that the inclusions begin to be visible even to the naked eye.
- I1 – I2 – I3: “included”, which means that the inclusions are clearly visible to the naked eye.
Is diamond clarity really important?
A diamond with a poor degree of purity has more inclusions, which directly affect the brilliance. Since inclusions hinder the refraction and return of light, the lower the degree of purity, the more “milky” and opaque the diamond will appear.
Color refers to the natural tint inherent in white diamonds.
During the growth of the diamond, within its atomic structure, atoms of other elements can be inserted which affect the color of the stone.
If the stone is composed of only carbon atoms, its color is “white”.
The presence of nitrogen atoms gives the stone a more or less intense shade of yellow.
The scale set by the Gemological Institute of America is used to determine to which degree of color a stone belongs.
What is the color of the diamond?
The more “colorless” a diamond is, the rarer it is. The industry standard for color grading is to rate each stone against a master set and assign a letter grade from “D” (colorless) to “Z” (light yellow).
Is the color of the diamond important?
Color is the second most important of the 4Cs because the degree of color directly affects the appearance of the stone. Diamonds with a poor color grade may appear slightly yellow instead of the desired brilliant white.
The carat denotes the weight of a diamond. The carat is the unit of measurement of diamonds and precious stones in general (sapphires, rubies, emeralds, etc.) and is written ct. A carat is divided into 100 cents called points and corresponds to 0.20gr; for a stone weighing 0.45ct, it is said to be “45 points”. The adoption of the carat as a unit of measurement of the weight of diamonds dates back to the mists of time: it seems that the first precious merchants weighed diamonds using carob seeds (hence the term carat) as a reference.
What is a diamond carat?
The carat indicates the weight of a diamond, not the size. One carat equals 0.20 grams. Diamond carat charts Carat weight can appear differently in different diamond shapes such as round brilliant, princess, pear, oval, cushion, marquise, emerald, radiant or heart. A diamond can have a greater carat weight without appearing larger and two diamonds of the same carat weight can vary in size if one is cut deeper than the other. In other words, it is important to note that carat weight does not necessarily denote size. Is a higher carat weight better? Carat weight alone does not determine the value of a diamond. For example, two one-carat stones can vary greatly in price when clarity, color and cut are taken into consideration. When this is understood, it is clear that large diamonds of unmatched quality are rare.