Diamond grading

Diamond grading The brilliance and elegance of diamonds make them some of the most dazzling and desired gemstones in the world. Each diamond is unique and special, but understanding its classification is essential to select the perfect jewel that suits your preferences and budget.

diamond grading blog
diamond grading blog

In this guide, we’ll explain the basics of diamond grading, focusing on the famous “4Cs”: Cut, Clarity, Color, and Carat. By learning these key facts, you’ll be prepared to make informed decisions and discover the magic of diamonds in all its glorious glory. Join us on this fascinating journey into the world of diamonds!

The 4Cs: The Pillars of Diamond Grading

The “4C” system is widely recognized as the standard for diamond grading and evaluation throughout the world. Each “C” represents an essential characteristic that determines the quality and value of a diamond. Next, we will analyze in detail each of the pillars of diamond grading:


The cut of a diamond refers to the way the gem has been cut and how it interacts with light. A proper cut maximizes the brilliance, fire and beauty of the diamond. Well-cut diamonds reflect light exceptionally, giving them a dazzling brilliance. Different cut grades, such as “excellent”, “very good”, “good” and “fair”, indicate the quality of the cut and its impact on the overall appearance of the diamond.


Clarity refers to the presence or absence of internal inclusions and flaws in a diamond. These features can be minute inclusions (tiny internal blemishes) or small external blemishes. The clarity scale determines the purity of the diamond, from “internally flawless” (IF) to “visible inclusions” (I3). Higher clarity diamonds tend to be more valuable as they have greater transparency and a cleaner appearance.


The color of a diamond refers to the presence or absence of shades of yellow or brown. Colorless diamonds, classified as “D” on the color scale, are the most valuable due to their purity and transparency. As you move through the letters of the alphabet, from “D” to “Z”, a gradual increase in yellow or brown color intensity is observed. However, it is important to note that there are rare colored diamonds, known as “fancy diamonds”, which exhibit intense and unique hues, such as blue, pink or deep yellow.


Carat is a measurement of weight used for diamonds. One carat equals 200 milligrams. A larger diamond size is often associated with a higher carat, but it is essential to consider that the other 3Cs also influence the overall appearance of the stone. As the carat increases, the price of the diamond tends to increase due to its scarcity and demand.

These four pillars of diamond grading combine to determine the value and quality of a gemstone. By understanding how diamonds are evaluated and graded in each of these aspects, you will be prepared to make informed decisions in choosing the perfect piece of jewelry that reflects your individual style and preferences.

The cut of a diamond

The cut of a diamond is a fundamental factor influencing its appearance, brilliance and beauty. Cut refers to the way the gem is cut and polished, as well as the quality of proportions, symmetry, and finish. The proper cut maximizes the brilliance, sparkle and exquisite beauty of the diamond.

A well-cut diamond efficiently captures light and directs it towards the top of the stone, creating sparkle and brilliance. Poor cuts can negatively affect the appearance of the diamond, as light can escape from the sides or bottom instead of reflecting up.

The most common cut grades used in diamond grading are:

  • Excellent: Diamonds with an excellent cut grade have perfect symmetry and proportions. They reflect light optimally, resulting in exceptional brilliance and maximum utilization of the diamond’s potential.
  • Very Good: Diamonds with a very good cut grade also have excellent appearance and reflect light effectively. Although they may have small variations in symmetry and proportions, they are still high quality diamonds.
  • Good: Diamonds with a good cut grade show good brilliance and reflect light well. They may have slight imperfections in symmetry and proportions, but still offer an attractive appearance.
  • Regular: Diamonds with a regular cut grade may have significant deficiencies in symmetry and proportions, negatively affecting their brilliance and overall appearance.

It is important to note that the cut of a diamond should not be confused with its shape. Shape refers to the outer contour of the diamond, such as round, princess, emerald, and others, while cut refers to how the inner and outer facets have been cut and polished to maximize brilliance.

When selecting a diamond, it is advisable to look for one with an excellent or very good cut, as this ensures maximum brilliance and beauty. However, it is important to consider your personal preferences and available budget, as higher cut diamonds may command a higher price. The cut is a key factor that you should not overlook when choosing the perfect diamond that suits your tastes and needs.

The clarity of a diamond

Clarity is another important aspect in diamond grading, as it refers to the presence or absence of inclusions and internal flaws in the gem. These inclusions are small natural blemishes that form during the diamond creation process. Clarity is assessed using a standard scale ranging from “internally flawless” (IF), where no inclusions are detectable under 10x magnification, to “visible inclusions” (I3), where inclusions are visible to the naked eye.

The clarity scale is made up of the following grades:

  • Internally Flawless (IF): No inclusions or blemishes are detectable under 10x magnification. These gems are extremely rare, which makes them true jewels of great value.
  • VVS (Very, Very Slightly Included):
  • – VVS1: Extremely small inclusions can be detected under a 10x magnifying glass, but they are difficult to see even for a professional.
  • – VVS2: The inclusions are slightly more visible than in the VVS1 grade, but they are still very small and difficult to detect.
  • VS (Very Slightly Included):
  • – VS1: The inclusions are small and can be seen with difficulty under a 10x magnifying glass.
  • – VS2: Inclusions are slightly more visible than in the VS1 grade, but still require a magnifying glass to spot.
  • YES (Slightly Included):
  • – SI1: Inclusions are visible under a 10x magnifying glass, and may be visible to the naked eye in some cases.
  • – SI2: The inclusions are more noticeable than in the SI1 grade and may be visible to the naked eye in some diamonds.
  • I (Included):
  • – I1: Inclusions are visible to the naked eye and can affect the transparency and brilliance of the diamond.
  • – I2: Inclusions are even more noticeable and can have a significant impact on the appearance of the diamond.
  • – I3: The inclusions are large, numerous and drastically affect the transparency and beauty of the diamond.

It is crucial to note that most inclusions are not visible to the naked eye and are usually only detected under a magnifying lens. Additionally, the location, size, amount, and type of inclusion can influence a diamond’s clarity grading.

When choosing a diamond in terms of clarity, it is recommended to go for diamonds that are classified as VVS, VS or SI, as they offer good value for money. However, the choice of clarity also depends on your personal preferences and the available budget. When evaluating a diamond’s clarity, it’s essential to consider how inclusions can affect its beauty and brilliance, and balance that factor with other important aspects such as cut, color, and carat.

The Color of a Diamond

Color is another key aspect in diamond grading. Although diamonds appear colorless to the naked eye, most diamonds have a slight color cast. The diamond color scale is used to determine the presence and intensity of shades of yellow or brown in the gem.

The commonly used color scale is made up of the following categories:

1. D – F: These diamonds are classified as colorless and are extremely rare. They are considered the most valuable due to their high transparency and their ability to reflect light dramatically.

2. G – J: These diamonds are classified as “near colorless”. To the naked eye, they may appear colorless, but may show a slight yellow or brownish hue when compared to higher grade diamonds.

3. K – M: These diamonds have a more obvious color tone and are considered “lightly colored”. The yellow or brown hue may be visible to the naked eye, although its intensity may vary within this category.

4. N – Z: These diamonds have a more pronounced color tone and are classified as “colored”. They may show deeper shades of yellow or brown, becoming more and more visible as we move up the scale.

It is important to note that the choice of diamond color depends on your personal preferences and the visual effect you want to achieve. Higher grade diamonds (D – F) are often the most valuable, but slightly lower grade diamonds (G – J) can also be great choices, as they can offer a virtually colorless appearance at a more affordable price.

It is essential to evaluate the color of the diamond in different lighting conditions and compare it with diamonds of a similar grade to appreciate any color differences. Also, it is important to consider that in some cases, color tones can favorably interact with certain jewelry designs, creating a unique and distinctive style.

Ultimately, the choice of diamond color is a personal matter and depends on your aesthetic preferences and budget. Consider your individual tastes and find the right balance between color quality and other factors like cut, clarity and carat to find the perfect diamond to suit your needs.

The carats of a diamond

The carat is a measure of weight used for diamonds and other gemstones. A carat is divided into 100 points, which means that a 0.50 carat diamond can also be expressed as 50 points or 1/2 carat. The weight of a diamond influences its size and, in general, the higher the carat, the larger the size of the diamond.

It is important to note that the size of a diamond is not the only determining factor of its value. The other 3Cs (cut, clarity, and color) also play a crucial role in the quality and price of a diamond. A larger diamond is not necessarily more valuable if it is not of good quality in terms of cut, clarity, and color.

The choice of carat depends on your personal preferences, the available budget and the purpose of the diamond. It is important to keep in mind certain key aspects:

1. Budget: Higher carat diamonds tend to command a higher price. Therefore, it is important to set a budget and find a balance between the size and quality of the diamond that fits your financial possibilities.

2. Personal Style: Determine what size diamond best suits your taste and lifestyle. Some people prefer a more discreet and elegant diamond, while others may prefer a larger, more striking diamond.

3. Proportion to Other 3Cs: Consider how the size of the diamond relates to the other key aspects of grading, such as cut, clarity, and color. Find a balance between these factors to get an overall quality diamond.

Remember that the choice of carat is a personal matter and that there is no “ideal” diamond size. The most important thing is to find a diamond that you love and that meets your expectations in terms of appearance and quality.

Additional considerations

In addition to the 4Cs (cut, clarity, color, and carat), there are other important considerations when grading diamonds. These additional aspects can affect the overall quality and appearance of the stone. Here are some additional considerations to keep in mind when choosing a diamond:

1. Fluorescence: Fluorescence refers to the reaction of a diamond to ultraviolet light. Some diamonds can exhibit fluorescence, which can range from none to strong. Fluorescence can affect the appearance of the diamond in different lighting conditions. Some diamonds may show extra shine under ultraviolet light, while others may appear slightly cloudy. Fluorescence evaluation is a subjective and personal consideration.

2. Proportions: In addition to the cut, the diamond’s proportions also play a role in its overall appearance. Proper proportions allow light to reflect and refract correctly within the diamond, maximizing its brilliance and beauty. Things to consider include the relationship between table size (diamond top) and depth, as well as facet symmetry and the angle of the pavilion and crown.

3. Certification: When buying a diamond, it is important to look for a certificate of authenticity and grading issued by a recognized and impartial gemological laboratory. Certificates, such as those issued by the GIA (Gemological Institute of America) or the AGS (American Gem Society), provide detailed information on the 4Cs and other relevant aspects of the diamond, providing confidence and transparency in the purchase.

4. Style and personal preferences: Ultimately, your choice of diamond should also reflect your personal preferences and individual style. Consider your tastes in terms of size, shape, jewelry configuration, and overall design. The goal is to find a diamond that suits your personality and makes you feel special.

Remember that each diamond is unique, and the combination of the 4Cs and other additional aspects will determine its uniqueness and value. Take the time to explore different options, seek expert advice, and make an informed decision based on your priorities and preferences.


In conclusion, the classification of diamonds through the 4Cs (cut, clarity, color and carat) is essential to select the perfect jewel. Each of these aspects influences the appearance, quality and value of a diamond. By understanding and considering the 4Cs, as well as other additional factors such as fluorescence, proportions and certification, you will be able to make informed decisions when choosing a diamond that suits your taste and budget.

Do not forget that the choice of a diamond is a personal decision, and the most important thing is to find a stone that you fall in love with and that reflects your style and personality. Whether you are looking for a diamond with an excellent cut that sparkles brilliantly, impeccable clarity that conveys purity, a color to suit your preferences, or a carat size that complements your jewelry, understanding diamond grading will help you find it. the perfect jewel.

Make sure you get a certificate of authenticity and classification from a recognized entity, which will provide confidence and transparency in your purchase. Explore different options, compare diamonds and ask for expert advice to make the best decision.

Ultimately, diamonds are symbols of beauty and durability. Their eternal brilliance and timeless charm make them exceptional jewellery. Enjoy the experience of discovering the magic of diamonds and find the perfect jewel that will accompany you in special moments and will last over time.


When looking for information on diamond grading, the 4Cs and other related aspects, here are some helpful resources:

1. Websites of gemological laboratories:

– Gemological Institute of America (GIA): https://www.gia.edu/

– American Gem Society (AGS): https://www.americangemsociety.org/

– International Gemological Institute (IGI): https://www.igi.org/

These laboratories are internationally recognized and offer detailed information on diamond grading as well as certification services.

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