The four C’s: Cut, color, clarity and carat weight.
Cut: Cut is a factor that greatly impacts it's fire, brilliance and sparkle. People often think of the cut as the shape, however, the cut refers to a diamond's proportions, symmetry, and polish.
The major components from top to bottom are:
- the crown - the top of the diamond from the table to the girdle
- the table - the large, flat facet on the top of the diamond
- the girdle - the perimeter of the diamond, dividing the crown from the pavilion
- the pavilion - the distance from the girdle to the bottom of the pavilion, called the culet
The proportions of a diamond refer to the relationships between table size, crown angle, and pavilion depth. A wide range of proportion combinations are possible, and these ultimately affect the stone’s visual appeal and value. Diamond graders refer to a cut scale ranging from Excellent to Poor. Ideal cut diamonds are in the Excellent cut classification, but not all Excellent cut diamonds are Ideal cut. A diamond that is Ideal cut has been cut meticulously in the perfect proportions and angles to allow a visual “hearts and arrows” desired effect.
Clarity: Diamonds form deep within the earth, under extreme heat and pressure. This creates unique birthmarks called inclusions if they are internal or blemishes if they are external. Clarity refers to the absence of these characteristics within a diamond. Every diamond is unique, with it's own natural characteristics; flawless diamonds are exceptionally rare.
The GIA clarity scale is as follows (most valuable to least valuable):
- Flawless (FL) – No inclusions are visible to a skilled grader under 10x magnification
- Internally Flawless (IF) – No inclusions and only minor surface blemishes are visible to a skilled grader under 10x magnification
- Very, Very Slightly Included (VVS1 and VVS2) – Inclusions are difficult for a skilled grader to see under 10x magnification
- Very Slightly Included (VS1 and VS2) – Inclusions are fairly visible under 10x magnification but can be classified as minor
- Slightly Included (SI1 and SI2) – Inclusions are noticeable to a skilled grader using 10x magnification
- Included (I1, I2 and I3) – Inclusions are obvious under 10x magnification as well as to the naked eye and may affect transparency and brilliance
Color: The color of a diamond greatly affects it's value. Diamonds are valued for how closely they approach colorless - the less color, the higher their value. The exception to this is fancy colored diamonds, such as pinks and blues, which lie outside this color range. The industry standard for grading color, developed by GIA, lists a range of D (representing colorless) to Z (light yellow or brown color). Each of these color distinctions are so subtle it can be difficult to discern accurately to the untrained eye. Diamonds are graded for color from the backside (table down) and the less color in a diamond, the more valuable it becomes. The further away from D color, the warmer the tones become until they are a light yellow. Staying within the D – I color range will insure a whiter color for your diamond. This grading scale does vary slightly between different diamond grading professionals i.e. AGS and GIA versus EGL.
Carat: Diamonds are measured in metric carat weight: one carat is equal to 0.2 grams. A carat is divided in to 100 points. For example, a .50ct diamond equals 50 points. Even a fraction of a carat can make a considerable difference in cost so precision is crucial. Generally the heavier a diamond, the more valuable it is. The truth of this statement may differ depending on the quality of the other three “Cs”. You can have two similarly weighted diamonds that are drastically different in price because one has Flawless clarity with D (colorless) color and the other has SI2 clarity with I (slightly yellow) color.