“Until the middle of the twentieth century, there was no agreed-upon standard by which diamonds could be judged. The Gemological Institute of America (GIA) created the first, and now globally accepted standard for describing diamonds: Cut, Color, Clarity and Carat Weight. Today, the 4Cs of Diamond Quality is the universal method for assessing the quality of any diamond, anywhere in the world. The creation of the Diamond 4C’s meant two very important things: diamond quality could be communicated in a universal language, and diamond customers could now know exactly what they were about to purchase.”

*source: http://4cs.gia.edu/en-us/4cs-diamond-quality/

In this section you’ll find a comprehensive guide to the well-known 4 C’s. Let’s dive in...


Diamonds get their fame and magnificent brilliance from their ability to transmit light and sparkle so intensely. This is largely due to a diamond’s cut which, when done properly, works to unveil its brilliance. Of the 4C’s, Cut is the most important because it has the greatest effect on a diamond’s beauty and brilliance.

Not to be confused with a diamond’s Shape, a diamond’s cut is really about how well it’s facets interact with light. Skilled craftsmanship are required to cut a stone so its proportions, symmetry and polish work together to maximize the amount of light that is reflected back to the observer’s eye.

The GIA Diamond Cut Scale for standard round brilliant diamonds contains 5 grades ranging from Excellent to Poor. Compared to the other C’s, cut is the most complex and difficult to analyze. In determining the quality of the cut, the diamond grader evaluates the cutter’s skill in the fashioning of the diamond. They will also take into account the design and craftsmanship of the diamond, including its weight relative to its diameter, its girdle thickness (which affects its durability), the symmetry of its facet arrangement, and the quality of polish on those facets. It’s proportions and facets are evaluated to see how well it interacts with light to create desirable visual effects such as:

  • Brightness: Internal and external white light reflected from a diamond
  • Fire: The scattering of white light into all the colors of the rainbow
  • Scintillation: The amount of sparkle a diamond produces, and the pattern of light and dark areas caused by reflections within the diamond

At Mint Diamonds, we do not recommending sacrificing on cut when selecting the perfect diamond for your engagement ring. Other areas have some wiggle room, but the impact of cut on the overall beauty of your diamond is too important to chance. The best ways to ensure you choose a diamond with ideal cut characteristics are to 1) Always choose a diamond with an “Excellent” Cut and Symmetry Grading on the GIA diamond report, and 2) Consult with a Mint Diamonds expert before making your final purchase.


Gem-quality diamonds occur in many hues, from colorless to light yellow or light brown, and are graded based on their absence of color. A chemically and structurally perfect diamond has no color or hue, like crystal-clear water, therefore colorless diamond are the most valuable and rarest on the color scale. Other natural colors (blue, red, pink for example) are known as "fancy”, and their color grading is differs from white colorless diamonds.

Many of the color distinctions found in diamonds, which dramatically affect value, are so subtle that they are invisible to the untrained eye. In an effort to establish a universally accepted diamond color-grading system that would benefit both the jeweler and the consumer, GIA created the D-to-Z scale. The scale starts with D, representing a perfectly colorless diamond, and moves downward to Z as stones show progressively more yellow and brown hues. Diamonds are sorted into their color grade by comparing a stone under controlled lighting and precise viewing conditions to a set of master stones of established color value (Yellow or Brown diamonds must exhibit more color than a Z master stone in order to be considered “fancy”). Since its inception, the GIA color-grading scale has become the global standard for diamond professionals.  


During the intense process of heated and pressurized carbon transforming into a diamond, a variety of internal and external characterics may be developed. Small crystals can become trapped in a diamond when it’s forming, and sometimes as a crystal grows it can develop irregularities in its atomic structure. Diamond Clarity refers to the absence of these internal characteristics, called Inclusions and external characteristics, called Blemishes. Like colorless diamonds, those without inclusions or blemishes are extremely rare. However, most characteristics are invisible to the naked eye and can only be seen with magnification.

Evaluating diamond clarity involves determining the number, size, relief, nature, and position of these characteristics, as well as how these affect the overall appearance of the stone. While no diamond is perfectly pure, the closer it comes, the higher its value.

Like the color scale, GIA developed a clarity grading scale in order to establish a universally-recognized system. The globally-adapted GIA Diamond Clarity Scale has 6 categories, some of which are divided, for a total of 11 specific grades:

  • Flawless (FL) - No inclusions and no blemishes visible under 10x magnification.
  • Internally Flawless (IF) - No inclusions visible under 10x magnification.
  • Very, Very Slightly Included (VVS1 and VVS2) - Inclusions so slight they are difficult for a skilled grader to see under 10x magnification.
  • Very Slightly Included (VS1 and VS2) - Inclusions are observed with effort under 10x magnification, but can be characterized as minor.
  • Slightly Included (SI1 and SI2) - Inclusions are noticeable under 10x magnification.
  • Included (I1, I2, and I3) - Inclusions are obvious under 10x magnification which may affect transparency and brilliance.

Because many inclusions and blemishes are too small to be seen by anyone other than a trained diamond grader, it is very important to have an expert give an accurate assessment of your diamond. To the naked eye, a VS1 and an SI2 diamond may look identical, but these diamonds are significantly different in both quality and value.


The carat is the diamond’s physical weight, measuring its apparent size in metric carats. One carat equals ⅕ or 0.20 grams and is subdivided into 100 points. This allows very precise measurements to the hundredth decimal place. A jeweler may describe the weight of a diamond below one carat by its ‘points’ alone. For example, a 0.90 carat diamond is 90 points or a “ninety-pointer.” Carat weight is the most objective grade of the 4C’s, as it can be measured using a calibrated gem scale.

All else being equal, diamond price increases with diamond carat weight because larger diamonds are more rare and desirable. For example, a 0.50 carat diamond may be $1,500 per carat, while a 1.00 carat diamond with identical Cut, Color and Clarity may be $5,500 per carat, due to 1.00 carat diamonds being significantly more rare. But two diamonds of equal carat weight can have very different values (and prices) depending on variations in the three other factors of the 4C’s.