What Are The 4 C's of Diamonds & How To Rate Them

August 26, 2022

What are the 4 C’s of diamonds? The 4 C’s of diamonds represent a diamond’s cut, color, clarity, and carat weight. These four factors impact a diamond’s price, beauty, and rarity.

Each diamond must be examined to determine the best value for your money. After getting a diamond examined using the 4 C’s of diamonds, you will know the diamond’s quality and be able to estimate the diamond’s value.

The 4 C’s of Diamonds

Fine diamonds are among the world’s most coveted gemstones. Here at Bling Advisor, we take our diamonds seriously— giving you access to the best diamond quality out there! So, how is the value of a diamond determined? What is considered a well-cut diamond? What makes for the perfect diamond shape? What makes the perfect diamond color grade?

It can be challenging to know which diamond appears to represent the best value for your money, with many diamonds to choose from. The 4Cs of Diamonds were created to standardize how diamonds are valued and, as such, provide an invaluable tool.

Experts have created this simple international diamond grading system using the 4 C’s of diamonds:


The cut creates a diamond’s coveted sparkle and brilliance. When you look at the surface of a diamond, you’ll notice that there are many surfaces, called facets, that reflect light. Of the 4 C’s, the diamond’s cut most dramatically affects the beauty of a diamond. The stone’s overall proportions — the size and position of its facets — make up the cut.  

Experts have studied the optimal proportions of a diamond that create the most sparkle, and a stone that falls within these parameters is considered ideal.

Some commonly used terms regarding refraction and light:

  • Brilliance— the combination of all white light reflected from the surface and the inside of the diamond.
  • Dispersion— flashes of color you see in a polished diamond. Dispersion is also known as fire.
  • Scintillation— flashes of light you see when the diamond, the light, or the observer moves. 

Too Shallow Diamond Cut

When a diamond is cut too shallow, the diamond loses scintillation because the light is lost through the bottom of the stone. Shallow cuts are not preferred, but they can be found for a lower cost.

diamond cut too shallow

Too Deep Diamond Cut

When a diamond is cut too deep, it will lose brilliance because the light is lost through the side of the diamond before it reaches the surface. This cut is not preferred either.

diamond cut too deep

Ideal Cut

Ideal diamonds make up roughly the top 3% of diamonds. In a diamond with an ideal cut, light enters and returns through the top of the diamond.

ideal diamond cut

Diamond Color

Another factor that determines the value of a diamond is its color. Although there are some exceptions in rare, colored diamonds, the more valuable a diamond is, the less color it has. Completely colorless diamonds are scarce.

Color is measured using a letter grade scale. The diamond is manually compared to a master set to determine its color range. This range goes from a light yellow to completely clear, of “colorless.”

The GIA created a color scale that shows approximate ranges of color grades. Diamonds graded D, E, and F are considered colorless by many gemologists.

diamonds gia chart
4cs of diamonds

Diamond Clarity

Diamond clarity is measured by the existence or absence of visible flaws. Minor blemishes, even those unseen to the naked eye, on the surface of a diamond can alter the brilliance of a diamond and affect its value.

Flawless: No internal or external diamond clarity characteristics

Internally Flawless: No internal diamond clarity characteristics

Very, Very Slightly Included: Difficult to see under 10X magnification

Very Slightly Included: Inclusions not typically visible to the unaided eye

Slightly Included: Visible under 10X magnification and may be visible to the unaided eye

Included: Inclusions visible to the unaided eye

Diamond Carat Weight

Carat weight is typically the first characteristic of a diamond that we think of. The term carat refers to the weight of a diamond, not its size. A larger, heavier diamond does not always equal a more prominent sparkle, either. The sparkle comes from a well-crafted cut. You may notice that some diamond jewelry describes the carat weight as CTTW, which includes the total carat weight between all of the diamonds in the piece. Carat weight has the most considerable effect on a diamond’s price.

how to rate diamonds carat weight

What is the most important of the 4 C’s of diamonds?

Of the 4Cs of diamonds, we would say that the most important between cut, color, carat, and clarity would be the cut of the diamond.

Diamonds are highest valued based on cut, so it’s the most important of the 4 Cs! A Diamond’s cut also makes a diamond shine more brightly than any other gemstone.

Pro Diamond Quality Buying Tips:

  • If you are in the market for a beautiful, brilliant diamond, you may want to splurge on a higher-quality cut over a heavier carat weight. The cut maximizes sparkle without sacrificing quality!
  • A few things can affect a diamond’s appearance: band size, setting, and ring size. We’re here to help you get the best-looking diamond for your buck, so we use these factors to enhance a diamond’s natural beauty.  
  • Your diamond’s weight is significant when it comes to determining its value. A one-carat diamond will be considerably more expensive than a .90-carat stone, even if they are both within the same color, clarity grade, and nearly equal carat weight.


Many aspects can contribute to a diamond’s beauty, but beauty is in the eye of the beholder at the end of the day. A diamond’s ability to captivate the heart of that particular person may be all you need versus spending a ton of money on the perfect stone.

With the 4cs of diamonds, you can now see how a diamond is graded and next time you buy loose diamonds, be sure to use the above grading reports in mind.

At Bling Advisor, we also help you find precisely what you are looking for in a diamond. Instead of offering a list of limited customization options to choose from, we can bring your dream engagement ring to life!

Send us your design today! We have access to the industry’s best suppliers so that we can find the ideal diamond for you.

Are you looking for the perfect diamond engagement ring? Contact us, and we will source the perfect diamond for you!

See our blog post on natural diamonds vs. lab-created diamonds.

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