Four C’S of Diamond Buying

Carat, Color, Clarity, and Cut

Carat Weight

Simply put, the greater the carat weight, the rarer and thus more valuable the diamond becomes. A metric carat is defined as 200 milligrams. Each carat is subdivided into 100 ‘points.’ This allows very precise measurements to the hundredth decimal place. A jeweler may describe the weight of a diamond below one carat by its ‘points’ alone. For instance, the jeweler may refer to a diamond that weighs 0.25 carats as a ‘twenty-five pointer.’ Diamond weights greater than one carat are expressed in carats and decimals. A 1.08 carat stone would be described as ‘one point oh eight carats.’ Visually, there’s little difference between a 0.99 carat diamond and one that weighs a full carat (1.00), however, the price differences between the two can be significant.

All else being equal, diamond price increases with diamond carat weight because larger diamonds are rarer and more desirable. However, two diamonds of equal carat weight can have very different values (and prices) depending on the other factors of the diamond’s 4C’s.

Color Grade

Color is one of the more noticeable attributes of a diamond and has a heavy impact on the price of the stone. Diamonds range from colorless to yellow or light brown – the less color, the rarer the diamond. After ‘Z’ on the color scale, diamonds become fancy yellow, which cost more because of their rarity.

Diamond color scale

Clarity Grade

Diamonds are composed of carbon mostly. During the formation process, speck of pure carbon and other elements become trapped inside, giving each diamond its unique fingerprint. These ‘inclusions’ help identify the clarity of your diamond. The international standard for grading diamonds requires examination under a gemscope at 10x magnification power. Diamonds are graded on a scale from Flawless to Included. The amount, size, and location of a diamond’s inclusions bears heavily on the price.

Cut Grade

Diamonds are renowned for their ability to transmit light and sparkle so intensely. We often think of a diamond’s cut as shape (round, heart, oval, marquise, pear), but what diamond cut actually does mean how well a diamond’s facets interact with light. Cut refers to the only man-made aspect of a diamond: how well a jeweler physically cut the diamond to give the stone its maximum brilliance and dispersion. Most people neglect this aspect of a diamond, but it can actually be instrumental in getting a diamond to truly shine. The better the cut, the better the brilliance of the diamond.

Of all the diamond 4Cs, the cut is the most complex and technically difficult to analyze. The thickness of the girdle, the depth of the pavilion, the crown height, etc. all play a part in the diamond’s brilliance. Ideal cuts give off the most brightness, fire, and scintillation:

  • Brightness: Internal and external white light reflected from a diamond
  • Fire: The scattering of white light into all the colors of the rainbow
  • Scintillation: The amount of sparkle a diamond produces, and the pattern of light and dark areas caused by reflections within the diamond