Know The 4 C's

The 4 C’s: cut, clarity, color, and carat weight. These factors determine the diamond’s beauty, structure and value.


Carat (abbreviated “ct.”) refers to the diamond's total weight. Carat is distinct from the similar sounding “karat” which refers to gold's purity. The unit “carat” is defined as 200 milligrams or 100 ‘points' (about the weight of a paper clip).This allows very precise measurements to the hundredth of a decimal. A jeweler may describe the weight of a diamond by its ‘points’ alone. For instance, the jeweler may refer to a diamond that weighs 0.50 carats as a 'fifty pointer.’ Diamond weights greater than one carat are expressed in carats and decimals such as a 1.06ct. The price of a diamond will increase with diamond carat weight because larger diamonds are rarer and more desirable. Two diamonds of equal weight may be unequal in value depending upon other 4Cs. It is extremely important to remember that a diamond’s value is determined using all of the 4Cs, not just carat weight.


Diamonds are known for their ability to sparkle and shine! We often think about the shape of the diamond (round, princess, marquise, etc.) as the diamond's cut. However the diamond's proportions and symmetry are the diamond's cut. They create the facets that interact with the light is what really creates that dreaming sparkle. The cut is the biggest factor in creating the stone’s brilliance. Even a diamond of high quality can appear dull and lifeless with a bad cut. A diamond cut has three primary effects on appearance: Brilliance, Dispersion, and Scintillation. Brilliance is created by the white light reflected from the surface and the inside of a diamond. Dispersion is the breaking up of the white light into color on the visible spectrum (all the colors of the rainbow). Scintillation is the movement of the brilliance and dispersion or the amount of sparkle a diamond produces.


Natural diamonds are the result of carbon exposed to tremendous heat and pressure deep in the earth. This process can result in a variety of imperfections. Clarity is the assessment of these small imperfections on or within the diamond. The internal defects are called inclusions. The surface imperfections are called blemishes. Determining clarity involves understanding the number, size, relief, nature, and position of these characteristics, as well as how these imperfections affect the overall appearance of the stone. No diamond is perfectly pure. However, the closer it is to pure, the higher its clarity. At The Castle Jewelry, we evaluate our clarity based on the GIA grading standards. The GIA grading scale has the following categories:
  • Flawless (FL) -- No inclusions visible when magnified 10 times.
  • Internally Flawless (IF) -- No inclusions visible when magnified 10 times, tiny blemishes on the surface of the diamond
  • Very, Very Slightly Included (VVS1 and VVS2) – Tiny inclusions and blemishes visible to a trained grader when magnified 10 times
  • Very Slightly Included (VS1 and VS2) – Minor inclusions and blemishes are easy to spot when magnifies 10 times
  • Slightly Included (SI1 and SI2) – Inclusions and blemishes are easy to see when magnifies 10 times, sometimes even visible to the naked eye
  • Included (I1, I2, and I3) – Inclusions and blemishes are visible to the naked eye. I2 diamonds are so included that their brilliance and durability are affected.
  • FL/IF
  • VVS1/VVS2
  • VS1/VS2
  • SI1-SI3
  • I1-I3
  • Some inclusions and blemishes are too tiny to be seen by anyone other than a trained professional. For instance, to the naked eye, a VS1 and an SI2 diamond may look exactly the same. Nevertheless, these diamonds are different in terms of overall quality.


    Diamond color actually refers to the lack of color in a diamond. Diamonds do come in a variety of colors, some of them highly treasured (pinks, blues, even yellow) these are considered fancy color diamonds. Anyhow, in a white diamond, the presence of a yellow tint will lower the price of a diamond. A pure and structurally perfect diamond has no hue, and therefore greater in worth. The grading of a diamond color is rated on a D-Z scale (with the purest color being 'D'). The Castle Jewelry evaluates our diamond color based on the GIA grading standards. The GIA grading scale has the following categories:
  • Colorless (D-F): While there are differences in color between D, E, and F diamonds, they can be detected only by a gemologist in side by side comparisons, and rarely by the untrained eye.
  • Near Colorless (G-J): containing slight traces of color that are difficult to detect.
  • Faint Color (K-M): Beginning with K diamonds, color (usually a yellow tint) is more easily detected by the naked eye.
  • Very Light: (N-R): Diamonds in the N-R color range have an easily seen yellow or brown tint, but are much less expensive than higher grades.
  • Light (S-Z): Easily seen yellow or brown tinting to the untrained eye.
  • D-F
  • G-J
  • K-M
  • N-R
  • S-Z
  • Now you can see how each diamond is distinct and unique in its own way. Knowing the 4 Cs can be a huge help when selecting the perfect show stopping diamond. Check out our Precious Metals guide and become familiar with the different metal types diamonds are set in for rings, pendants and much more or head back to the Education Center