Diamond Math: 4C's

Diamond Math: 4C's + Craftsmanship = Five C's

4C's   |  Cut   |  Clarity   |   Color   |   Carat

The only purpose of a Diamond in life is to make us happy. When they don't, they are worthless. Mastering Four C's is a practical alternative for those who want to get engaged but don't have time to earn a gemological degree. 4C's is the time-proven system (courtesy of the GIA) that has helped millions of people purchase diamonds.

Just like with everything else, you get what you pay for when selecting a diamond. There is a reason why some seemingly identical diamonds are cheaper than others. 4C's is the best method for sorting the differences and making a smart choice.

How to use 4C's

The 4C's system is similar to a music equalizer. Instead of faders controlling each frequency, you get sliders for color, clarity, cut, and weight. The output is the diamond price. Their effect on the price is not equal; color and weight are major factors, clarity and cut are less significant.


You can shop in three different ways by choosing:

  • - budget and size, or
  • - budget and grade, or
  • - size and grade

Step 1. Select a budget

Be realistic with your expectations. Don't be that old lady from the Miracle on 47th Street:

  • "Do you have a 3-carat diamond?"
  • "Yes, we do."
  • "Top-color, ideal cut?"
  • "Yes. What is your budget?"
  • "500 dollars."
  • "... You are in luck! We have a flawless 3-carat diamond, and it's only $500!"
  • "You are kidding!!!"
  • "Yeah…. But you started first!"

A diamond engagement ring indicates your social status but does not determine it. Spending more than you can afford to show off is not smart.

First of all, you can always upgrade in the future. Most diamond grades are indistinguishable from one another without strong magnification. Nobody will be able to tell two stones apart, except for your bank account.

Step 2. Select a diamond grade

For your convenience, we combined color and clarity and named the property "grade" (+ means "or better clarity" ):

- J-K/SI-I is a budget grade (consider lab-grown as well)

- H-I/ SI1+ is a smart grade (VS1+ for emerald- and Asscher-cuts)

- F-G/VS+ is a premium grade

- D-E/VVS+ is a vanity grade


Unless they are visible with a naked eye, inclusions are a gift because they save you thousands on something no one can see. According to GIA, every clarity grade above SI2 is eye-clean. It means that without 10x magnification, a person cannot see any inclusions.


But unfortunately, half of the SI2 stones have inclusions that people can see without magnification. Even some SI1 stones have noticeable inclusions.

"Eye-clean" is not a grade but a subjective opinion that depends on the observer's eyesight, lighting conditions, depth perception, and even mental condition.


Eye-clean SI1 is the best clarity grade for brilliant cuts. VS2 is the lowest recommended clarity grade for emerald and Asscher-cut diamonds since their reflections do not mask inclusions well.


Diamond color grade is a major factor in a diamond's price because it reflects how rare the stone is. Completely colorless diamonds are rare but not necessarily the best-looking. Some feel that diamonds utterly void of color have a somewhat unnatural look, similar to cubic zirconia. A small amount of a yellow tinge can be useful, as it gives the diamond a more natural look.

Step 3 Select carat size

Size is measured in carats. People desire a specific carat size only because society pressures them to affirm their social status. The carat size alone without an appropriate grade is a waste of a diamond.

The great majority of people are willing to sacrifice carat size in favor of a better grade.

It is a common misconception that a person's height or the length of their fingers requires a certain number of carats. The ring style and personal preferences, however, must be taken into account.

Step 4 Cut is the king

GIA evaluates the cut grade for round diamonds only. When you choose a round diamond, GIA excellent cut grade is almost a must for the stone to retain its value. The excellent cut grade practically guarantees that the stone is beautiful and full of life.


In the GIA universe, the cut grade for fancy shapes does not exist. Symmetry is the key to the fancy diamond excellence. Excellent or very good symmetry is a must unless you are choosing an antique cut diamond.

The cut and symmetry are not negotiable. 

Beauty is in the eye of the beholder

The regret of a junky diamond lingers long after the joy of getting a bargain is forgotten. People enjoyed wearing diamonds centuries before they learned to sort the good ones from the bad ones. Each grade is not a measure of a stone's beauty but an indication of its relative rarity and value.

A perfectly symmetrical, completely void of color and inclusions diamond is not necessarily superior to a lower grade stone. It is just different but equally beautiful. Subject to personal taste. Roman poet Lucretius once uttered: "One man's meat is another man's poison."

The Fifth C - Craftsmanship

A jeweler's ability to make a setting that will enhance, not diminish, the diamond's look is the most critical factor.

Don't have an account yet? Register Now!

Sign in to your account