The 4 C's of Buying A Diamond

Are you planning to buy a diamond? We at A. T. Thomas Jewelers understand this is a significant decision that will symbolize love and commitment for the rest of your life. Our guide below will make your diamond-buying experience easier and more enjoyable. The most significant criteria a jeweler will use when grading a diamond are; Cut, Clarity, Color, and Carat Weight; more commonly known as the 4 C's of a diamond. The value of a diamond is determined by all four of these properties.

Diamond Cuts


The cut of a diamond is often confused and considered its shape. However, cut refers to diamond angles and proportions. Diamond cut is considered the most significant of the four C's, so it is worthwhile to understand how it affects diamond properties and values. Diamonds that are cut too deep, or too shallow can lose, or leak light through the sides and bottom. These diamonds will be less brilliant and valuable. Whereas, a well-cut diamond handles light better, creating more scintillation and sparkle, which lends to increased brilliance

Cuts of Diamond


Diamonds are graded for clarity under 10x magnification. Clarity ranges from flawless (perfect) to I (included). Below is the chart that certification societies have standardized for grading to describe diamond clarity.

  • F - Flawless: No internal or external flaws. Extremely rare.
  • IF - Internally Flawless: No internal flaws, but may have minor flaws on the outside. Very rare.
  • VVS1-VVS2 - Very, Very Slight Inclusions: Have very small inclusions. It's very difficult to detect inclusions under 10x magnification, even by a trained gemologist. VVS1 inclusions can only be seen through the pavilion. VVS2 inclusions are more visible.
  • VS1-VS2 - Very Slightly Included: Inclusions can only be seen under 10x magnification with some difficulty. VS1 inclusions are more difficult to see than VS2.
  • SI1-SI2 - Slightly Included: Inclusions are easy to see under 10X magnification and might be visible to the naked eye.
  • I1-I2-I3 - Included: Inclusions visible to the human eye.

Clarity of Diamond


Color refers to the presence or absence of color in white diamonds. Diamonds act as prisms and divide light into a spectrum of colors, reflecting it as colorful flashes called fire. The more colorless a diamond is the more colorful the fire will appear. Diamond colors generally range from D - Z for white and yellow diamonds. D is the whitest. Around S they become "Fancy" yellow diamonds.

Color  of Diamond


Carat refers to the diamond weight unit. One carat is equivalent to 200 milligrams. Sometimes, one carat is called 100 "points", so a diamond of 75 points weighs .75 carats. Carat weight is the easiest of the 4C's to determine. However, two diamonds of equal weight can have very unequal values, depending on their Cut, Color, and Clarity. A diamond's cost increases exponentially with an increase in weight. This is because larger diamonds are rarer than smaller diamonds and this rarity increases the value of a sizeable diamond.

Diamond Weights