44 School Street, Boston, MA

What are the 4Cs? How do you buy a diamond?

The “4C’s”

  • Four factors that make up the value of a diamond: color, clarity, cut and carat.
  • Each of these four factors plays a part in the pricing of a diamond.
  • You can prioritize certain factors over others.
    • For example, you can decide size is more important than color, or clarity is less important than color, etc..


  • Diamond color generally ranges from D (clear) to Z (toned)
  • Around S the diamonds become known as “Fancy” yellow diamonds.
  • The finest colors, around D, E, and F, are very clear.


  • Diamond clarity ranges from flawless/perfect to I (included).
  • Internally Flawless:exterior has some minor flaws
  • VVS1 (very, very slightly imperfect): minute inclusions that are extremely difficult to see. Inclusions are only visible through a loop magnified 10 times.
  • VVS2 (very, very slightly imperfect): minute inclusions that are difficult to see.
    • for both VVS1 and VVS2, the inclusions can only been spotted by someone who has had a lot of experience looking at diamonds, and the viewer must be using a loop magnified 10 times.
  • VS1,VS2(very slightly imperfect): have some very small inclusions. VS1 inclusions are more difficult to see than VS2.
  • SI1, SI2 (slightly imperfect): all have small inclusions.  These can only be seen in a loop.
  • I1, I2, I3(visibly included): have inclusions that may be seen by the naked eye.


  • There are 100 points in a carat.
  • Diamonds will cost more per carat weight.
  • Carat is probably the least important factor in determining the value and quality of a diamond. In other words, when purchasing a diamond, bigger does not necessarily mean better.


  • Cut is what unleashes the brilliance and lets the diamond truly shine.
  • Diamond cutting requires knowledge and skill.
  • Precise cutting will optimize the diamond’s optical properties and allow light going in to be refracted and reflected back out, and the color to be dispersed.
  • Because of the complexity in cutting a diamond, Cut is the most critical of the “4C’s”.
2015-08-04T10:38:43+00:00July 28th, 2015|

About the Author:

Skylight Jewelers
Our shop is also our studio, where we design and create exquisite jewelry. Skylight Jewelers has been creating custom made jewelry for over 35 years. We take great pride in our work and sign each piece. Our specialty is engagement rings, wedding bands, and our enchanting collection of fine jewelry which includes colored gemstones, pearls and moonstones. All of our Pieces are created in gold or platinum using a mélange of modern, traditional, and ancient techniques. We'd love for you to come by and view our latest creations as well as watch us create in our studio!