4 C’s

Designated this way by its initials Cut, Color, Clarity and Carat.


  • Cut is truly important, since it has a great influence on both brightness and glow of the diamond.
  • Hence the importance of keeping the right proportions of the Cut, since this is crucial in unleashing the diamond true potential.

As we observe on the above image, the light behavior by entering the stone shifts remarkably according to cut proportions. A well cut diamond with symmetrical and straight facets will reflect light beautifully, i.e. light enters through the upper part or crown, then refracts on inner walls and goes back up through the crown, providing the diamond’s signature sparkle. On the contrary, when perfect proportions are not achieved, i.e. diamond is shallow or deep, light escapes through the pavillion.

This is how you grade a diamond cut: Poor, Acceptable, Good, Very Good and Ideal. The keys to get to this classification are symmetry, polish and proportions.

The four attributes of diamond quality, the 4 C’s, are all of utmost importance. However, the single attribute that man has the ability to perfect on a stone, is the diamond cut, task that must be performed only by experts.

Rough diamond cutting initial phase.

The cut of the stone is connected to all the other attributes of quality. The cut will influence the diamond carat weight and the geometric proportions will affect the diamond color. A superb polishing can even help to get rid of external blemishes and therefore naturally enhance the diamond clarity.

The difference between the cut of a diamond and the making of a diamond.

In Nature there are no two rough diamonds identical. Performing a diamond cut is the ability of getting the best possible product from a rough. By definition, the cut is the preset faceted arrangement of the diamond. Since it is through the cut that the finished product is made, how the faceted arrangement is created is referred to as the 'make' of the diamond.

Analysis of optical characteristics of a rough diamond.


  • The second C is for Color, since is what the eye observes right after the glow and brightness of the stone.
  • The color of a diamond makes reference to the lack of color (this applies only to colorless diamonds). As diamonds approaches to the colorless level they get the best grade, except for Natural Fancy Color Diamonds, see Learn about Fancy Color Diamonds.
  • olorless diamonds or “white” exist on a scale that has many hues, from bright colorless to pale yellow. These subtle differences are graded from “D” (colorless) until “Z” (light yellow) and are grouped into these 6 categories:


The definition of what diamond clarity is, describes the diamond's whole appearance in relation to the number of both internal and external imperfections in the stone. Each stone is assessed and then graded according to a standardized grading scale.

Diamond clarity is divided into six categories, of which many contain a number of clarity grades. As the clarity grades move along the scale to a lower clarity grade, the overall value of the diamond decreases. Still, even though the clarity grade may drop, it might not necessarily affect the overall appearance of the stone.

The table below defines the different levels of clarity for both white and color diamonds.

In a colorless diamond, clarity is a very important feature to keep in mind. However, diamond clarity does not play as much of an important role in fancy colored diamonds as it does in colorless stones. When choosing a fancy colored diamond, the color and intensity are far more important than the clarity of the diamond.


The weight greatly impacts the cost of the stone since the cost increases considerably per carat. For instance, a 1.00 carat diamond is not exactly half the price of a 2.00 carat diamond. If the weight drops, even if it is only by a few points down to the lower carat weight, the price of the stone will be significantly lowered.

A carat refers to the unit of measure used to describe the weight of the diamond. A long time ago, because of their size, the seeds of the Carob were used on precision scales as units of weight for small quantities of precious stones. This tradition continued through time, thus we refer to the measurement unit as carat.

Diamonds that come with a grading report will indicate the exact weight to the nearest hundredth of a carat weight. Each carat is divided into 100 points, so if a diamond weighs 1/2 of a carat, meaning 50 points, its weight would be recorded as 0.50 ct

Diamond Shapes

Diamond shapes are quite different between each other and the quality is determined by its unique characteristics.


Round diamond is by far the most sought and popular shape. For almost 100 years, diamond cutters have experienced with the most advanced theories of light behaviour and precise optical calculations to optimise glow and brightness in a round diamond.


Within the no round diamond group Princess cut is one of the most popular shapes. It’s one of the favorites for engagement and wedding rings. Traditionally it has a square shape although it may present rectangular shape also.

For a square Princess cut, the ideal Lenght to Width ratio is from 1.0 to 1.05. If the choice is a rectangular princess cut, the ideal is ratio over 1.10


Emerald cut stands out for its pavilion with rectangular facets to create a unique optical appearance. Due to its wide and open table this cut highlights the clarity of a diamond.

For a classical emerald cut, the ideal is a Lenght to Width ratio between 1.30 and 1.40.


This beautiful shape is almost identical to the emerald cut, except it is square and with rectangular facets on the pavilion.

Ideal Lenght to Width ratio between 1.00 and 1.05


Marquise or Navette cut maximises weight in carats, giving the appearance of a much larger diamond.

The ideal Marquise ratio is between 1.75 and 2.20.


Oval shape has a beautiful glow similar to the round brilliant.

The ideal ratio for this shape is between 1.33 and 1.66.


Rounded corners are the hallmark of this cut and when it comes to its use in jewelry it’s highly versatile.

The ideal ratio for the square Radiant cut is between 1.00 and 1.05 and for a more rectangular shape is above 1.10.


Pear cut is a highly required choice in jewelry with a rounded tip and a sharp opposite.

The ideal ratio is between 1.45 and 1.75.


Heart cut is a must in jewelry, the quintessential symbol of love.

The ideal for this shape is a ratio between 0.90 and 1.10.


This cut has rounded corners and bigger facets to increase the brightness.

The ideal ratio is between 1 and 1.05 when square. But for a rectangular shape the ratio should be above 1.15.

Diamond Certification

What is a diamond certification done by an independent specialized laboratory?

Although it’s not the only world renowned laboratory, the Gemological Institute of America (GIA), established in 1931, is the world-class authority on diamonds and colored stones. Its work includes research and education in the field of gemology.

One of the GIA’s more significant services is provided by its GIA Laboratory which provides diamond grading services to describe the characteristics of loose diamonds. This information is issued by the GIA as the GIA Diamond Grading Report.

The GIA Diamond Grading Report (see copy below), issued for diamonds weighing 0.20 carats or more, provides a full quality assessment of a diamond and contains the following data:

  • Date (of report)
  • Report Number
  • Laser Inscription Registry (if requested)
  • Shape and Cutting Style
  • Measurements
  • Color Grade
  • Clarity Guide
  • Finish (quality of surface condition as well as information of the facets)
  • Polish (general condition of surface)
  • Symmetry (exactness of diamond’s outline)
  • Fluorescence (strength and color of diamond)
  • Plotting Diagram (approximates shape and cutting style of stone)
  • Key to Symbols, GIA Clarity Scale, GIA Color Diamond Scale, Proportion Diagram, and Security Features (of report to ensure authenticity). As an optional service, a full color image of the diamond may also be included.


Founded in Antwerp in 1975 IGI is the largest organization of its kind in the world with offices and gem labs in Antwerp, New York, Hong Kong, Mumbai, Bangkok, Tokyo, Dubai, Tel Aviv, Toronto, Los Angeles, Calcutta, New Delhi, Thrissur, Jaipur, Surat, Chennai, Ahmedabad and Hyderabad.

It was the first lab in the world in sealing its diamonds for security reasons. In addition they patented the IGI Laserscribe System Mark which is used to inscribe identification data on the stone using a laser beam. Also it was one of the first labs able to identify treated natural diamonds and synthetic diamonds.


For over three decades EGL USA has portrayed state-of-the-art research lines in the gemological field in the USA with a distinguished balance between science and services. Its head office is located in the heart of the diamond district in New York and it has also an office in the west coast, in Los Angeles.


This prestigious lab is owned by the Antwerp World Diamond Centre (AWDC) which represents the belgian diamond industry. It’s been approved by the World Federation of Diamond Bourses (WFDB) and the International Diamond Manufacturers Association (IDMA) the world’s two most eminent industry leaders.

Why Antwerp? Since 1447 it’s been synonym with diamonds with the oldest set of rules record to commercialize goods, said document establishes that "no one within the city of Antwerp is to buy, sell, pawn or pass on any false stones imitating diamonds, rubies, emeralds and sapphires..." Antwerp has been a diamond center for centuries. The world's first stock exchange was founded there, trading everything from copper and silver to diamonds and gold.