What are the 4Cs? Everything You Should Know About Diamond Quality



You’re a first-time diamond buyer, but you want to be sure you’re making an informed decision. Let’s break down the specifics of what every buyer should know so you can be confident in your purchase.


In the diamond industry, there is a universal method of grading that ensures two things: a diamond’s quality can be objectively measured, and that quality can be communicated in a universal language. This grading system is called the 4Cs. 


The 4Cs of Diamond Quality was created by the Gemological Institute of America (GIA) and is a globally accepted standard for diamond grading. Each “C” represents a unique method of measurement that ultimately determines a stone’s value: cut, color, clarity, and carat weight.







A diamond’s cut grade measures how well the stone’s facets refract light to create that famous sparkle. Often overlooked, this measurement is the most important of the 4Cs—but also the most complicated. 


When a diamond is cut, the end goal is for the stone to sparkle as much as possible. This is accomplished through a meticulous combination of symmetry, polish, and proportion. Each of these elements work together to give the stone its face-up appearance, and they are all taken into consideration when grading the diamond.  


Proportion: Measuring the diamond facets. Each facet of a diamond has a unique ideal proportion designed to maximize the amount of light it reflects.

Polish: The smoothness of the outer surface of the diamond.

Symmetry: The exactness of the shape of the diamond. If the angles aren’t correct, the diamond facets will not reflect light. 

Face-Up Appearance: The brightness, fire, and sparkle of the stone.


Over the years, there have been many variations of cutting styles for diamonds. It is a process that is continually evolving, as independent cutters often develop their own unique cutting patterns. While you can still buy diamonds with older cutting styles, like European or Mine cut, they won’t likely receive a good score because the GIA cut grade is based on round brilliant diamonds (the current standard). Today, the standard cut for a round brilliant diamond is one with 58 facets.


You may not be able to identify your diamond’s cut grade on your own, but it is helpful to understand what this measurement represents. If you’d like to dive further into the details of a diamond’s symmetry, polish, and proportions, visit the Gemological Institute of America for more information.




The color scale measures a diamond’s lack of color. Any presence of yellow tint will lower the stone’s value.


Diamonds exist in a variety of colors, but white is typically the most valuable. All diamonds on the D - Z (colorless - light color) scale are still considered white diamonds, though hints of yellow or brown increase as the scale descends. Fancy colored diamonds, like yellow or pink, are graded on a separate color scale. Color is graded from the bottom of the stone because a diamond’s sparkle can make the color even harder to detect. 


Color can be difficult to see because the differences are very subtle, but there will always be a premium for stones in the D - F range. Many buyers are content with a stone in the G - K range, where hints of color are hidden in the diamond’s sparkle and generally lower in cost.



A diamond’s clarity refers to the internal and external imperfections of the stone. This is a major factor in diamond evaluation and often the one buyers pay the most attention to.


The clarity grade of a diamond is determined by the severity and visibility of its inclusions (internal imperfections) and blemishes (external imperfections). Inclusions and blemishes can occur while the diamond is being formed in the earth, during the cutting and polishing process, or from wear.


To grade a diamond’s clarity, the stone is viewed under 10x magnification and assessed accordingly. For example, a blemish in the center of the diamond will be much more noticeable than an inclusion along the edge. While clarity is important to be aware of, it’s not the most important aspect of a diamond, as most buyers won’t look at their diamond under magnification ever again after purchase.

Keep in mind that flawless diamonds are incredibly rare and will come with a hefty price tag. The clarity most commonly purchased is from VS1 - SI2.


To maximize your budget when buying a diamond, consider a stone in the “Slightly Included” range. It will have imperfections that are easily visible under magnification, but will appear perfectly clean to the naked eye.   




Carat is the measurement of the diamond’s weight. It is the most commonly understood of the 4Cs as it is relatively obvious to the untrained eye.


In gemstone jargon, a jeweler may reference a diamond in terms of its points. A diamond carat (1.00) is broken down into 100 points, meaning, a ½ carat diamond weighing 0.52 carats could be referred to as a “fifty two pointer”. Or, a “.52 carat diamond”. A diamond price will increase as the carat weight increases since a larger diamond is considered more rare and valuable.






A diamond’s carat weight is often synonymous with its size. However, they are not the same—a heavier weight does not guarantee that the diamond looks bigger. Two diamonds with the exact same shape and carat weight can appear to be different sizes.


Carat weight and cut grade go hand in hand in creating a beautiful stone. If a stone has not been cut correctly, it may hold more weight in the bottom, causing it to appear smaller from the top.


In summary, a general understanding of the 4Cs is essential for all diamond buyers. These measurements determine the cost and quality of your diamond and ensure its specifications are known and legitimate.






Another factor to consider when purchasing a diamond is your ring’s setting. Discuss with your jeweler which setting best suits your particular size of diamond, stone selection, or financial means. If you want a big look but don’t have the budget, consider a diamond alternative or a gemstone.


With a dedication to fine jewelry crafted from quality materials, June creates modern heirlooms made to last. Shop our collection or create a custom ring with our design team.