Just like buying a new house or a new car, buying a diamond is a very special and exciting moment!
But since no two diamonds are exactly alike, choosing the right diamond for you can be quite confusing if you don’t know what to look for and how diamond quality is measured.
Diamond grading is actually quite recent since it wasn’t until the 1940s that the Gemological Institute of America (GIA) established the “4Cs” and the International Grading System as a scale to evaluate diamond quality.
The 4Cs have now become the worldwide standard to evaluate diamond quality.
So, once you understand the 4Cs, you will have no trouble finding the perfect diamond for you!
Let’s get into it right away….
A diamond’s cut is crucial to the stone’s final beauty and quality; of all 4Cs, it is also the most complex to achieve and determine. And whereas we often think of diamond cut as shape, GIA grades a diamond cut on how its facets interact with light.
Diamonds get their fire and brilliance from their cut, which is optimized so that the diamond facets capture the most light, then reflect it and disperse it more effectively on the diamond table (upper face).
In other words, well-cut diamonds with optimum proportions will have the best shine, as opposed to diamonds that are too flat or too thick.
The proportions, symmetry and polish of each diamond part determine the diamond cut quality.
There are mathematical guidelines for the angles and length ratios at which diamonds must be cut to achieve maximum brilliance and fire.
Based on these guidelines, GIA sets a grading scale for diamond cut quality, ranging from Excellent to Poor.
The GIA color-grading scale is only used to rate white diamonds for which you could say that diamond color is all about what you can’t see.
The more colorless diamonds are the better they are able to diffuse light to the colors of the rainbow.
According to GIA’s grading scale, diamond color ranges from D (colorless) to Z (light yellow or brown).
Many of these color distinctions are so subtle as to be invisible to the untrained eye, and many years of experience are necessary to spot them accurately. However these slight variations make a very big difference in diamond quality and price.
The wide spectrum of white diamond colors, according to GIA’s color grading scale.
Most diamonds have internal flaws – or inclusions – which, if too big or too many, may affect diamond transparency and brilliance.
Hence, the less inclusions diamonds have, the clearer they are.
A flawless (FL) diamond.
GIA has set a clarity grading scale, ranging from Flawless (FL) to Included 3 (I3) and determined under 10x magnification.
Diamond weight is the most obvious attribute of GIA’s 4Cs, as it refers to diamond size. It is measured in carats.
The higher the carat weight, the rarer and pricier the diamond is.
However, it is important to keep in mind that two diamonds of equal carat weight can highly differ in quality depending on their cut, color and clarity.