Diamond Colour The GIA (gemological institute of America) has 2 types of colour grading scales, the D-to-Z Colour Grading and Coloured Diamond Colour Grading. The D-to-Z Colour Grading is based on the lack of colour by comparing a stone under controlled lighting.while the Coloured Diamond Colour Grading is based on the presence of colour.if the colour is deep enough it will get a fancy colour rating D-to-Z color-grading scale is the industry’s most widely accepted grading system. The scale begins with the letter D, representing colorless, and continues, with increasing presence of color, to the letter Z (yellow or brown usually) Many of these color distinctions are so subtle that they are invisible to the untrained eye; however, these distinctions make a very big difference in diamond quality and price. Though a colourless diamond is considered most valuable, diamonds do have some degree of colour in them. A colour scale established by GIA (Gemological Institute of America) assigns a letter to the degree of colourlessness found in a diamond. Beginning with D and ending with Z, each descending letter denotes an increasing amount of light yellow, brown or gray in the diamonds. D E F – The stone appears colourless, however a gemmologist can identify the minute traces of colour found in these diamonds. G H I – These diamonds have a hint of colour that is not noticeable to the untrained eye, almost colourless. J K L – Faint traces of colour are visible when the diamond is looked at face up. M to Q – These diamonds have light traces of colour. R to Z – The colour in the diamond is obvious even to the untrained eye. With the exception of a few natural fancy colours like blue, pink, purple or red, the more natural colour a diamond has, the lesser it is worth compared to its counterpart colourless diamonds. Opaque diamonds such as black diamonds go for a much smaller price than clear white diamonds. The yellow colour in diamonds comes from the traces of nitrogen found in them. One part in a million will cause a yellow tint to appear in the colour of a diamond.
Diamond Clarity The Diamond Clarity is graded based on the absence of inclusions and blemishes. Inclusions are small imperfections in the diamond while blemishes are on its surface. Small crystals growth trapped in a diamond during formation deep in the earth causes the inclusions. Natural diamonds are the result of carbon exposed to tremendous heat and pressure deep in the earth. This process can result in a variety of internal characteristics called ‘inclusions’ Evaluating diamond clarity involves determining the number, size, relief, nature, and position of these characteristics, as well as how these affect the overall appearance of the stone. While no diamond is perfectly pure, the closer it comes, the higher its value. Many inclusions and blemishes are too tiny to be seen by anyone other than a trained diamond grader. To the naked eye, a VS1 and an SI2 diamond may look exactly the same, but these diamonds are quite different in terms of overall quality and price. A diamond, with fewer inclusions, is both rare and more desired which also makes it more expensive. A diamond with a purity of IF to VS2 will sparkle with great intensity whereas diamonds with a purity ranging between SI1 and SI2 will only sparkle. Diamonds between I1 and I3 will lack any sparkle and life and its inclusions will be noticeable to the naked eye. The clarity of a diamond is based on the number, location, size and type of inclusions found in the stone. An inclusion is an imperfection or trace mineral in the stone that is visible under the magnification of a loupe. The fewer the inclusions, the clearer, brilliant and expensive the diamond will be. A flawless diamond is the one that has no inclusions. GIA has established a grading system to measure the type and size of these imperfections. Fl – Flawless, No inclusions and no blemishes visible under 10x magnification. rare and expensive. IF – Internally Flawless, No inclusions visible under 10x magnification, VVS1 – VVS2 – Very Very Slightly Included, Inclusions so slight they are difficult for a skilled grader to see under 10x magnification. VS1 – VS2 – Very Slightly Included, Inclusions are observed with effort under 10x magnification, but can be characterized as minor. An excellent quality diamond. SI1 – SI2 – Slightly Included, Inclusions are noticeable under 10x magnification, should not be visible to the naked eye when the stone is in the face up position. good quality diamond. I1 – I3 – Inclusions, Inclusions are obvious under 10x magnification which may affect transparency and brilliance. It is almost impossible to have a diamond without impurities. Often invisible to the naked eye, these natural blemishes are categorized as inclusions, which are internal and blemishes, which are external. While fewer such impurities will make the diamond more valuable, higher quality does not necessarily mean that the diamond is more beautiful than a stone of a lesser clarity, you have to keep in mind the cut quality of the diamonds in question, however it will make a difference in terms of how the diamond is priced. It is also important to note that while two stones may have the same clarity grade, one may have more inclusions more visible to the naked eye than the other due to the position of the inclusions.
Diamond Cut Cut is probably the most important and most challenging of the 4Cs to understand. The brilliance of a diamond depends significantly on its cut. A cut does not refer to the shape of the diamond. Rather, it refers to the the quality of the proportion of the angles with which the diamonds are cut to perfection. When a diamond is cut to ‘Excellent’ or ‘Very Good’ proportions, light is reflected from one facet to another and is dispersed through the top of the diamond, resulting in a burst of fire and brilliance. ‘Fire’ is a term for the flashes of colour one sees when you look at a diamond, while ‘brilliance’ refers to the sparkle. The diamond cut refers to how well a diamond’s facet interacts with light. Out of the Diamond 4Cs, it has the most influence on how bright a diamond will shine. Diamonds are renowned for their ability to transmit light and sparkle so intensely. We often think of a diamond’s cut as shape (round, emerald, pear), but a diamond’s cut grade is really about how well a diamond’s facets interact with light. Precise artistry and workmanship are required to fashion a stone so its proportions, symmetry, and polish deliver the magnificent return of light only possible in a diamond. The quality of cut is crucial to the diamond’s final beauty and value. And of all the 4Cs, it is the most technically difficult to analyze. The best proportionate round diamonds, with perfect angles, become the most beautiful diamonds.
Diamond Carat Weight The size of a diamond is proportional to its carat weight. When rough diamonds are cut and polished into finished diamonds, up to 2/3 of the total carat weight may be lost. Since larger rough gems of high quality are found less frequently than smaller rough gems of high quality, a single two carat diamond will be more expensive than two one-carat diamonds of the same quality. Although usually used to make quick references to the size of a diamond, the carat size (expressed as ‘ct’) is the measurement of the weight of a diamond. A carat is equal to 0.2 grams, which is about the weight of a paper clip. Each carat can be 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.’ All else being equal, diamond price increases with carat weight, because larger diamonds are rarer. But two diamonds of equal carat weight can have very different values, depending on three other factors within the 4Cs: Clarity, Color, and Cut. It’s important to remember that a diamond’s value is determined using all of the 4Cs, not just carat weight.