Looking for a beautiful and sparkling piece of diamond jewellery that also ranks higher on the quality scale? We can help you find just that! Let’s say you are out there looking at gorgeous diamond rings or stunning diamond earrings. You finally find something that’s appealing to your eyes and decide to buy it.
A common mistake that most buyers make is assuming that a shinier or bigger diamond that’s visually attractive is of the best quality. However, if cut and sized correctly, even a poorly graded diamond with multiple inclusions and blemishes will look mesmerising.
This is why you need to learn about the diamond grading scales! It is important for you to know and understand each scale and the respective grades and subgrades to help you make an informed decision about your purchase.
To start with, a diamond grading system comprises four different grading scales established to evaluate each of the 4Cs of the diamond.
These are the diamond’s cut, colour, clarity and carat weight. The value of a diamond is decided based on its 4Cs and the respective grades.
So, What Are the Different Diamond Grading Scales?
1. Diamond Cut Scale
A diamond’s cut is responsible for its brilliance, sparkle and fire. Here, brilliance refers to the total amount of light reflected from a diamond. Sparkle, also known as scintillation, is basically the pattern of light and dark areas along with the flashes of light that form when a diamond or its source of light is moved. Coming to fire, it is the dispersion of the reflected light into the colours of the spectrum.
All these factors are a result of a great cut and contribute to the beauty and allure of a diamond. To understand this better, let’s take into consideration a classic round brilliant diamond and its 58 facets. Each of these is cut with extreme precision and definition, leading to the formation of facets as small as two millimeters in diameter.
Another interesting thing about the cut is that it is often mistaken for the gem’s shape. However, the cut and shape are two different aspects of a stone. In this case, while brilliant is the cutting style, round is the shape or the outline of the diamond.
Expanding further on the cut, let’s tell you that it refers to the gem’s proportions, symmetry and polish. To understand this aspect in detail, let’s discuss about the key components of a standard round brilliant diamond from top to bottom. These include the crown, girdle and pavilion of the stone. Of the 58 facets of a round brilliant cut diamond, the 58th is an extremely small, flat facet below the pavilion, also called as the culet. On the flip side, the top-most large, flat facet is known as the table.
Here, the relationships between table size, crown angle and pavilion depth together are called as a diamond’s proportions. There can be multiple proportion combinations here that ultimately affect the diamond’s interaction with light and thereby its brilliance, sparkle and fire.
Based on its cut, a diamond can be placed into one of these five grades:
- Excellent
- Very good
- Good
- Fair
- Poor
2. Diamond Colour Scale
The next diamond grading scale is the colour scale that’s used to grade a diamond based on how colourless it is. You read that right! Most colourless diamonds may look similar to the untrained eye. However, they can be categorized into letter-based grades starting from colourless (being the most valuable) to near colourless and stones with hints of yellow or brown.
Given below is a detailed bifurcation of the same:
| Diamond Colour Grade | Colour |
| D – F | Colourless |
| G – J | Near Colourless |
| K – M | Faint Colour |
| N – R | Very Light Colour |
| S – Z | Light Yellow or Brown |
The diamond colour scale starts with the letter D constituting colourless diamonds going up to the letter Z comprising stones with a slight tint of yellow or brown. Here, each letter grade defines the specific colour or appearance of the stone. How they are graded, you ask? Well, each stone is compared to the other under controlled lighting as well as viewing conditions to complete the colour grading process.
While stones from different letter grades might display a very minor difference as far as colour is concerned, it still immensely affects the stone’s quality and price.
Please note: Here we are talking only about the colourless or white diamonds and not their fancy-coloured counterparts.
3. Diamond Clarity Scale
Did you know that diamonds were formed deep within the earth’s crust? Also, that they had to go through extreme heat and pressure during their formation? As a result, this stunning gem features a variety of inclusions (internal flaws) and blemishes (external flaws). Moreover, the type of flaws, their size, quantity, relief and placement play a major role in enhancing or decreasing the diamond clarity.
Diamonds without any flaws are exceptionally rare and valuable and fall under the highest grade on a clarity scale. On the other hand, the stones that have a high number of visible inclusions are ranked the lowest.
The diamond grading scale for clarity consists of 11 grades, including subgrades, and a grade is given to a diamond only after thoroughly evaluating it under 10x magnification. These grades and subgrades are as follows:
- Flawless (FL): The diamonds that fall under this grade display no visible inclusions and blemishes even when analysed using 10x magnification by a trained grader.
- Internally Flawless (IF): Only external flaws or blemishes can be seen when analysed using 10x magnification by a trained grader.
- Very, Very Slightly Included (VVS1 and VVS2): The internal flaws or inclusions in diamonds falling under these grades are absolutely minute and therefore difficult to spot even for an expert grader under 10x magnification.
- Very Slightly Included (VS1 and VS2): Here, the inclusions are extremely small and can vary from difficult to somewhat easy to spot for an expert grader under 10x magnification.
- Slightly Included (SI1 and SI2): A trained eye can easily spot the inclusions under 10x magnification.
- Included (I1, I2, and I3): The diamonds falling under these grades possess visible inclusions, which may highly affect the transparency and brilliance of the stones.
4. Carat Weight System
The last ‘C’ that affects the value of a diamond is its carat weight. All gemstones including diamonds are weighed in carats. Here, one carat is equal to 200 milligrams or 0.2 grams.
A carat is further divided into 100 points for precise measurement of weight of the stones. For instance, a 50-point diamond weighs 0.50 carats, a 75-point diamond weighs 0.75 carats, a 100-point diamond weighs 1 carat and so on.
However, interestingly, two diamonds that weigh the same can feature absolutely different values, all depending on the other 3Cs – cut, colour and clarity. Also, most diamonds used in the fine jewellery industry today weigh 1 carat or lesser.
Do note that even a slight difference in the carat weight can lead to a significant difference in the value. Therefore, being precise is of utmost importance.
Now that you know about the various diamond grading scales and the respective quality grades in detail, you should be able to concentrate on the factors that are the most important for you while shopping for the diamond jewellery of your dreams.
Did You Know?
That the Gemological Institute of America (GIA) created the 4Cs – cut, colour, clarity and carat weight) as a universal system for evaluating and determining the quality of any diamond, across the world.
If you are looking for high quality diamond earrings, pendants, bracelets and rings, Angara should be your ultimate jewellery shopping destination. Every piece here comes with a certificate of authenticity that features product details and information on the gemstone colour, carat weight, quality grade, etc. enabling you to make a confident purchase.
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Also Read: Diamond colour vs. Clarity – Which Is More Important?
