What do You Know about the International Diamond Grading System (4Cs)?

Every diamond is unique. Still, there is an international grading system of diamonds that features four main characteristics of a stone: Diamond’s Cut, Color, Clarity, and Carat. It is well-known as 4C’s grading system. This will help you to know more about the main characteristics that affect the diamond’s beauty and shine and will help to choose a stone that matches your wishes the best.


is the first and most important feature of a diamond that defines its beauty. The cut is not about the shape of a stone how everybody thinks, but about polish, symmetry, brightness, fire, scintillation, weight ratio, and durability. While creating a diamond, for the gem cutter it is important to find a balance between the size of a stone and its cut quality. In GIA’s system, each component is assessed individually, taking into account the relative importance of that component in the overall cut quality of the diamond.

There is a general scale from Excellent (Ideal) to Poor which describes the proportions of each cut grade:

Diamond's Cut Grading

- Excellent or Ideal - Diamonds with ideal proportions and even patterns of dark and bright areas allow the light to maximize its brilliance and sparkles.

- Very Good - Diamonds of this cut grade are very similar to the ideal ones. They feature excellent symmetry and polish.

- Good - Diamonds reflect almost all the light that dips into the pavilion but not so well as Very Good diamonds. Symmetry and polish are enough.

- Poor - Diamonds have very slight brilliance than others and may seem pale and dim. Average symmetry and polish.

Tip: The best solution will be to choose the Excellent (Ideal) or Very Good cut grade. The last one also reflects perfectly the light but for a lower price. The difference between these two cut grades is not visible by untrained eyes. If the budget is not enough, you can bravely choose a diamond with a Good cut. But make sure that the stone does not have excessive depth. In that case, it may seem smaller than the one with similar weight, but with a better cut.


is another important factor when choosing a diamond. The most valuable stones are colorless diamonds except fancy color ones like pink or blue which dosn't belong to the color scale.  

GIA offers the color grading scale from D, indicating colorless grade, to Z with a light hint of yellow or brown. 

Each letter grade has a clearly defined range of color appearance. It is recommended to set diamonds of D-G grades in white gold or platinum in order to maximize stone sparkle and brilliance. And vice versa, diamonds grading from H to M will beautifully look in yellow or rose gold.

Diamond's Color Grading

Tip: The bigger the diamond the easier is to determine shades of color. That is why we recommend choosing colorless grades for bigger diamonds. In the precious stones which are under one carat, it is very hard to notice some inaccuracies in color without special settings. So you can make a sacrifice of several color grades to the advantage of other characteristics.


Nothing is perfect, even diamonds. Natural crystals also have some imperfections which are called Inclusions (inner flaws) and blemishes (external flaws). Only 1% of all diamonds can be impressed by Flawless purity. Such crystals are very rare.

GIA International Clarity Grade System is used to determine the clearness of diamonds.

Diamond's Clarity Grading

- Flawless (F) - No inclusions and blemishes are visible under 10× magnification.

- Internally Flawless (IF) - No inclusions, only blemishes are visible under 10× magnification.

- Very, Very Slightly Included (VVS1-VVS2) - Inclusions are difficult to see for an expert under 10× magnification.

VVS1 - inclusions are visible only from the side of the pavilion.

VVS2 - inclusions are visible from the side of the crown.

- Very Slightly Included (VS1-VS2) - Very slight inclusions appear. It is hard for an expert to see them under 10× magnification.

- Slightly Included (SI1-SI2) - Inclusions are visible at 10x magnification.

SI1 - inclusions can be seen with the naked eye upon close examination from the side of the pavilion.

SI2 - from the side of the crown.

- Included (I1-I2) - Perceptible inclusions that can affect the clarity and brilliance of a diamond.

When planning your budget, keep in mind that diamonds up to SI1 clarity have no inclusions visible to the naked eye.

Tip: Choose Eye-Clean Diamonds. These diamonds have no inclusions visible from the crown and are significantly cheaper than the exceptionally rare FL and IF stones.


Diamonds are weighed in carats historically. One carat is equal to 0,2 g. Because big diamonds are very rare in nature, carats have a dramatic influence on the crystal’s price. A diamond of one carat will be more expensive than two diamonds of half carats with the same characteristics.

Diamond's Carat Grading

Tip: A diamond of 0,9 carats will cost 10-20% cheaper than a diamond of one carat. The saved budget can be used to select the best cut, color and clarity.