10 Things You Should Know About Diamond Grading
Diamond grading is a complex process that is performed to define the characteristics of a given diamond. The diamond grading system is a standardized, global way for jewellers, laboratories, and consumers to know about the quality of a diamond. Diamond grading basically is the assessment of small imperfections on the surface and internally. The surface flaws are called blemishes, and internal defects are known as inclusions. These minute, natural blemishes and inclusions are microscopic and thus, do not affect a diamond's beauty in any way. Diamonds with the least and smallest inclusions get the highest clarity grades.
Diamond grading is an integral part of the jewellery industry and one should know a few things about it. Here, we are sharing the 10 things you should know about diamond grading.
1. What is the need for Grading?
Before the current diamond grading system was in place, there were various methods available to quantify and qualify diamonds. In the 1800s, diamonds were sometimes graded using the letters A, B, and C to signify their quality. By the late 1800s, numerals like I, II, III, and IV were used to indicate a diamond’s quality, as well as AAA, AA, and A. Short descriptions were also used to express a diamond’s quality, but these descriptions varied from region to region. This inconsistency with signifiers made quality control and diamond trading on a global level very difficult.
After many years as a jeweller, Robert M. Shipley, Founder, Gemological Institute of America (GIA) noticed that the jewellery industry was lacking the standardization and scientific background that many other industries had. Therefore, he established the GIA and began informally teaching about the 4Cs of diamond quality. The 4Cs diamond grading system, created by GIA is the universally recognized grading system still in use today.
2. Who are the Graders?
There are various gemological institutes established across the world who evaluate the quality of diamonds. The gemological institutes are objective diamond graders that determine the attributes of the diamonds and gems. Their job is to be the judge and jury of each diamond - a responsible adult if you will. After all, when the diamonds are so expensive, would you trust the scale of the seller to determine the weight? Would you put your money on his expertise to determine its quality?
Over the years more and more such gemological institutes were established. Some of the most commonly known to date are: GIA (Gemological Institute of America), AGS (American Gem Society), IGI (International Gemological Institute), EGL (European Gemological Laboratory), HRD (Hoge Raad voor Diamant).
3. How does the 4Cs Diamond Grading System Work?
The universally accepted GIA diamond grading system is based on the 4Cs of diamond quality that helps in determining the value of a diamond. These four characteristics are Color, Clarity, Cut, and Carat Weight.
• Colour: Diamond colour refers to the relative amount of yellow, brown or grey body colour. Even a subtle difference in diamond colour can dramatically affect its value. Two diamonds of the same clarity, weight, shape and cutting style can differ in value based on their colour alone. GIA determines the degree of colourlessness in a diamond by comparing it under controlled lighting and viewing conditions to a set of master stones of established colour grades. Colours are graded on a scale of D-to-Z, wherein D represents colourlessness, and continues with increasing presence of colour to the letter Z (slight yellow or brown tint). GIA colour scale includes 23 colour grades that are subdivided into five subcategories: colourless (D-F); near colourless (G-J); faint (K-M); very light (N-R); and light (S-Z).
• Clarity: The clarity of a diamond refers to how flawless a diamond is. The diamond clarity chart of GIA has 11 clarity grades: Flawless (FL), Internally Flawless (IF), VVS1, VVS2 (Very, Very Slightly Included), VS1, VS2 (Very Slightly Included), SI1, SI2 (Slightly Included), and I1, I2, I3 (Included). The clarity grade of a diamond is determined by the size, number, position, nature, and colour or relief of any inclusions or blemishes.
• Cut: Talking about diamond cut, most people link it with the diamond's shape, whereas, actually it refers to the quality of the diamond's cut for a given shape. A diamond's cut grade represents how the diamond interacts with light, typically based on the proportion, symmetry, polish, brilliance, fire, and scintillation of the gem. Each diamond is accredited with a cut grade, from poor to excellent.
• Carat Weight: Carat weight is the unit of measuring the weight of a diamond. Carat weight is measured to the thousandth of a carat and then rounded to the nearest one hundredth. Specialized tools are used to ensure precise measurements. Weight plays a very important role when it comes to pricing of diamonds since they are priced per carat and there are lots of tricks on how to manipulate it on your behalf and save a lot of money.
4. Which is the Most Important C of the 4Cs?
When it comes to evaluating the quality of a diamond, the 4Cs live in parity. Generally speaking, moving up the scale in one of the grade charts will allow you to move down one scale in the other chart and stay with diamonds of the same value (roughly). For example, if you will buy one carat G SI1 diamond, it will cost approximately the same as a one carat diamond with H colour and VS2 clarity (one colour grade lower and one clarity grade higher).
You can also play with the weight of a diamond, by reducing the carat weight on one hand and increasing the clarity/colour grades and stay at the same price level. Most diamantaires would classify cut grade as the most important C out of the 4Cs. The reason being, how valuable a high clarity diamond or pure colourless diamond is if it is dull? After all, people buy expensive diamonds for their shine… for their sparkle!
5. What is Diamond Grading Charts?
For the longest time, diamond grading was evaluated on the basis of certificates that were a bunch of numbers, symbols, and angles presenting the diamond anatomy. It was then in 2007, GIA took the diamond grading one step further by introducing various diamond grading charts. These charts help people with the process of how to choose a diamond, which was not possible with the earlier certificates. After all, it's not easy to understand the cut quality of a diamond from the diamond's chart only.
The most famous and commonly used charts are the ones on the GIA certificate: Diamond Color Chart, Diamond Clarity Chart, and Diamond Cut Chart. When a diamond is graded according to the grading charts, besides for stating its various grades they are also put on the relevant chart in such a manner that you will know exactly how good it is.
6. What about a fifth "C"?
Technically speaking, there are no more C's. However, of late, there has been another criterion which people refer to as the Fifth C of Diamond Grading and it is the 'Gemological Certificate'. Any jeweller can issue a certificate specifying the 4Cs of a bespoken diamond. But the question is are they qualified and professional enough to do so? Over the years we have seen many reputable jewellery companies issuing their own certificate of authenticity as for the diamond's quality and attributes. But those companies have the incentive to lie (or at least to round it up) towards their own sake. A minor "mistake" of grading a diamond as D instead of E means a lot of money. Therefore, I would suggest to only trust the objective certificate of a gemological institute and the GIA's certificate is known to be strict non-compromising and accurate.
7. How can you get your Diamond Graded?
If you are looking to find out the general characteristics of your diamond, you can head to a local jeweller who may be able to provide a free appraisal of the approximate features of your diamond. But if you are looking to get more accurate information regarding the grading of your diamond, you can have your diamond certified by a laboratory such as the GIA, EGL, AGS, or HRD. These laboratories will assess your diamond and provide a report for your stone.
8. Do All Laboratories Use the GIA Diamond Grading System?
While the GIA’s grading system is the most popular and widely accepted, other laboratories use different grading systems and terminology also. The IGI, EGL, and HRD use similar grading terminology to the GIA, but the AGS, another top laboratory in the industry, uses a very different grading system. The AGS grades diamonds on a scale from 0-10 in terms of colour, clarity, and cut.
9. Is it Important to have your Diamond Certified by a Laboratory?
When purchasing a diamond, especially one of 1ct+, it is always recommended that you purchase a GIA certified stone or at the very minimum have an appraisal or paperwork that documents the characteristics of the stone. However, when selling your diamond, you do not need your diamond to be certified (unless it is a coloured diamond).
10. Looking beyond the 4Cs of Diamond Grading
Diamond grading reports are amazingly helpful and nowadays it is absolutely not recommended to buy a diamond without a certificate, but at the end of the day, a diamond's appeal also counts. Although the 4Cs form an integral part of a diamond, it's not everything. Don't forget to look at the diamond and decide if you like it or not.
So now you know what you should be doing before buying a diamond. To verify a diamond's quality before purchase, be sure to review its Diamond Grading Report and GIA Certificate.
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