A Guide To Diamond Quality and Value

Diamonds are the most beautiful, rare and cherished precious gemstone and is judged by 4 distinct factors that, when combined, can help to determine its value. These factors are called the 4 C’s: Colour, Cut, Clarity and Carat.

First created by the GIA (Gemological Institute of America), these 4C’s are now the global standard that has been accepted for describing and determining the value and quality of a diamond. The creation of a diamond’s 4C’s has meant that there is now a universal language to communicate the value of a diamond, and is a way for customers to know exactly what they are about to purchase and invest their money into.


The weight of a diamond is conveyed in Carats. The metric value of a carat is determined as 200 milligrams and every carat can be further subdivided into 100 ‘points’ allowing for a very precise and accurate measurement of the weight of the stone. I.e: 1 carat = 100 points.

The larger the diamond, the rarer and desirable it becomes – meaning that the price of the stone will increase. However, it is important to note that two diamonds of the same carat can extremely differ in price and this all depends on the other 3 factors of the diamonds 4C’s.


Diamonds are a naturally occurring stone that has been created over hundreds of years of carbon being exposed to tremendous levels of heat and pressure deep within the earth. Due to the natural creation of the stone, the diamond can acquire a range of internal and external characteristics known as inclusions and blemishes.


To be able to correctly evaluate the clarity of the diamond, we must be able to determine the number, size, nature and position of these imperfections as these will affect the overall appearance of this precious gemstone. Even though no diamond is exactly pure, the cleaner it is, the higher it’s value.


Although many of these inclusions and blemishes are too small to be seen by the naked eye, other than that of a trained diamond grader, there can be extensive differences between gradings. Even though an FL and an Eye-Clean Si2 diamond can look exactly the same, these diamonds can differ substantially in overall quality, and thus in its value.


Diamond-Quality-FactorsDiamonds are acclaimed for their tremendous ability to transmit light and shimmer and sparkle. Although it is often thought that the diamond’s cut is the shape of the diamond (ie: round, square, heart, oval); in fact, the diamond’s cut grade is referred to how well its facets interact and reflect light.

It takes careful artistry and impeccable craftsmanship to precision cut a diamond to that its proportions, polish and symmetry deliver the most rewarding and magnificent return of light.

diamond’s cut is the most crucial portion of the 4C’s in terms of its eye-catching beauty and value, however, out of all of the 4 factors, it is the most complex and difficult to analyse. The accuracy in which your diamond is cut will dramatically impact its fire, brightness and scintillation. Fire is the term that is used to describe the way that the light that enters the diamond is broken down into different colours.

In order for a diamond to make the best use of light, it must be cut into the right proportions. If the cut is too deep, the light can escape through the sides of the diamond or through the bottom. However, if the cut is too shallow, the light will escape through the bottom before it has time to be reflected by the facets.


The grading of the colour of a diamond is based on the absence of colour. A completely pure diamond has absolutely no colour, shade or tint and has the highest value. The colour-grading system that is used to determine the colour value of a diamond measures the degree of colour by comparing a loose diamond with a ‘Master Set’ under very specific grading conditions.

Share this post