Understanding The 4 CS Of Diamonds

The 4 Cs of Diamonds refer to cut, color, clarity, and carat weight - the most important characteristics to understand when making a diamond purchase. Gradings of the 4 Cs help determine the quality and value of the diamond.

Like a fingerprint, each diamond is unique, and each has specific qualities that determine its value.  Each of the 4 Cs is graded on a scale. The scale was established in the early 20th century by the Gemological Institute of America (GIA). It created this universal method for assessing the quality of any diamond, anywhere in the world. Besides establishing a universal standard for all jewelers, it also means that diamond customers can know exactly what they are doing when making an important diamond purchase.

Each of the 4 Cs is, of course, a separate quality, and each is important when comparing diamonds. As a rule, we suggest a high-quality cut, because the cut, more than anything else, impacts a diamond’s beauty and brilliance. But remember that all four qualities interact with each other to create a unique and special diamond. And the most important factor to remember is how the diamond appears to you, to the naked eye—and how beautiful it is, overall. Something as special as a diamond should not be  purchased based on its laboratory grading report alone.  At The Private Room, our master jewelry craftsmen understand the interrelation of the 4 Cs, and focus on every diamond to enhance its unique beauty. We also focus on every customer, and help you find the perfect diamond for your budget. 



The cut of a diamond refers to its proportions, symmetry, and the polish of the surfaces, or facets. This is what creates a diamond’s sparkle and brilliance. That’s why we say  that cut is the most important quality. Because usually, customers want the most sparkle that their budget allows. A beautiful, sparkling diamond comes from how well the diamond is cut and crafted. A badly cut diamond can look dull. That’s why it’s possible for a smaller, but well-cut diamond to be more expensive than one that is slightly larger or of a rarer color.

We often think of a diamond's cut as shape (round, emerald, pear, marquise, etc.), but a diamond's cut is really about how well the diamond's facets play with light. What makes diamonds special is how they reflect light and sparkle so intensely. The better the cut of a diamond, the more light is reflected, and the more brilliant it will look.  So, when deciding what diamond to buy, go with the best cut grade that you can afford.

Among the components that the GIA Cut Grading Scale considers are brightness, fire, and scintillation:

Brightness assesses how much white light is reflected from the top of the diamond, or  the table. 

Fire is flashes of color, and how the diamond scatters white light into all the colors of the rainbow. This happens when light enters the diamond, and is reflected around its interior, bouncing off its facets, and then leaving through the top. Some beams of light separate and create brilliant flashes of color.

Scintillation is flashes of light and dark areas in a diamond. Besides flashes of color, have you ever noticed the flashes of light and dark areas you see in a diamond ring when you move your hand? That is scintillation.

And finally, Polish is what gives a diamond its beautiful finish on the outside surfaces.

It’s the balance and craftsmanship of these three  – fire, brilliance, and scintillation, plus expert polish -  that make a top-quality diamond.


Most often, a diamond’s cut is graded as excellent, very good, good, fair, or poor. Here’s an explanation of the GIA Cut Grading Scale:

Excellent – the top tier in diamond quality based on cut, polish, and symmetry. These are outstanding stones with an even pattern of bright and dark areas.

Very Good – diamonds that are nearly in the top tier of diamond cut quality. Any small areas of darkness or dullness in the pattern are barely noticeable.

Good – diamonds that are less sparkling. They have moderately sized dull or dark areas in their pattern.

Fair – a less desirable diamond cut quality. They have large areas of darkness or dullness.

Poor – diamonds that are cut too deep or too shallow, so they lose light out of the sides and bottom. They have a mediocre appearance.

At The Private Room, our designers and master jewelers are among the best in the industry. We only use the top cut grades, so you can be confident about your purchase.



Diamond color is an important quality that affects a diamond’s beauty. Diamonds naturally occur in many colors, including gray, white, yellow, green, black, brown, and pink. but most commonly, they are white or colorless.  The GIA Color Grading Scale is the global standard for diamond grading. The scale ranges from D (colorless) to Z (light yellow or brown). Usually, the naked eye can’t tell the difference between the color variations, but these distinctions make a big difference in diamond quality and price.

A pure and perfect diamond has no color or hue, like pure, clear water. And generally, the closer the diamond is to a “D” grade (colorless), the rarer and more valuable it is. But remember that  the brilliance, or sparkle of a diamond is created from the way it’s cut, not from its color.

At The Private Room, we carry diamonds ranging from D to G, the four highest color grades. But remember that a diamond with a color grade of F-G might be better for you than one that is D-E. And because the price is lower, you then have the possibility to buy a larger diamond. And of course, all diamonds at The Private Room are expertly cut.



Natural diamonds are created by extreme heat and pressure deep in the earth. This process means that practically all diamonds contain internal organic features that are called inclusions, blemishes, or flaws. Clarity refers to these natural inclusions.

The clarity grade on the GIA Clarity Scale measures the amount of inclusions on the surface and within a diamond. Although these may affect the diamond’s appearance, they are unique, and give the diamond personality or character, just like a beauty mark on a beautiful face. But the fewer visible inclusions there are, the higher clarity grade and the more expensive the diamond will be.

Generally,  VS and SI diamonds are considered to be the best value for your money.  Why is that? Flawless (FL) and Internally Flawless (IF) diamonds have the highest clarity quality grade. But, since budget is probably your first concern when making a diamond purchase, you might want to consider these other grades. For the best value, you can select a beautiful diamond with inclusions that cannot be seen through the crown of the diamond without magnification. This quality is known as eye-clean, and they are usually  diamonds with a VS or SI clarity grade. These diamonds are much less expensive, but they look the same as the higher grades.

Clarity is evaluated by the GIA Clarity Grading Scale with the following grades:

FL - Flawless Diamonds

  • No internal or external characteristics
  • Less than 1% of all diamonds are FL clarity
  • A flawless diamond is incredibly rare because it’s nearly impossible to find a diamond 100% free of inclusions

IF - Internally Flawless Diamonds

  • Some miniscule surface blemishes may be visible under a microscope
  • IF diamonds have no inclusions within the stone
  • Visually eye-clean

VVS1, VVS2 - Very, Very Slightly Included Diamonds

  • Minuscule inclusions that are difficult even for trained eyes to see under 10x magnification
  • VVS clarity is rare and results in an eye-clean appearance

VS1, VS2 - Very Slightly Included Diamonds

  • Minor inclusions ranging from difficult (VS1) to somewhat easy (VS2) to see at 10x magnification
  • Usually considered a great value

SI1, SI2 - Slightly Included Diamonds

  • Inclusions are noticeable at 10x magnification
  • If eye-clean, SI1 diamonds are often an excellent value
  • SI2 inclusions may be detectable to a keen eye, especially when viewed from the side

I1, I2, I3 - Included Diamonds

  • I clarity diamonds have obvious inclusions that are likely to be visible

The Private Room only uses diamonds graded IF – SI1.

Remember, diamonds are made underground in enormous pressure and heat, so natural inclusions or blemishes are inevitable. No diamond is perfect; they are each unique.




The term “carat” comes from the word “carob,” because in the ancient world, carob seeds were used as a reference for diamond weight.

The price of a diamond increases with carat weight, because larger diamonds are rarer and of course, more desirable. Perhaps because of advertising or the movies, carat weight has become a status symbol. But when it comes to diamonds, bigger is not always better.

Carat refers to a diamond’s weight, not its size, which can be confusing. Two one-carat diamonds can look very different, and can have different values and prices, based on the other 4 Cs - cut, color, and clarity.

That’s why It's important to understand the 4 Cs, and remember that a diamond's value is determined by all of them, not just carat weight.

At The Private Room, we consider every aspect of the diamond. We cut and design for maximum beauty, sparkle, and brilliance, so you can be sure that you are getting the best value.


So, let’s recap. Which is the most important of the 4 Cs?

Here is how they are generally ranked:

Cut: Cut is the most important aspect of a diamond because it impacts its beauty the most. Look for brilliance and fire. Be ready to accept a lower grade in clarity or color to ensure an exceptional cut.

Color: Color is the second most important aspect to focus on. A diamond should look white or colorless to the naked eye.

Clarity: The third most important characteristic is clarity. Look for diamonds that are eye-clean. The blemishes and inclusions of a diamond should not distract from its brilliance or fire.

Carat: Carat weight is the last aspect to consider. Brilliance and sparkle will always outshine weight. So be open to lowering your carat weight to ensure you purchase a beautiful diamond. 

With these fundamentals in mind, remember that a diamond is a precious whole, and should be looked at in totality. Think about what is important for you and the one you love. Most important, when making a diamond purchase -- ­trust yourself; trust your instincts, and trust your mind, eye, and heart when reacting to the piece of jewelry. Your special diamond should be the one you never want to take off - regardless of the 4 Cs.