Guide Step One
Master the 4 C's
There are four main aspects of a diamond you will need to master. They are Cut, Colour, Clarity and Carat Weight. You have probably heard them referred to the 4C’s. The following 4 information boxes will guide you through everything you need to know, to confidently walk into any jewellery store.
While a Diamond’s cut grade ranges from Excellent, Very Good, Good, Fair and Poor – Excellent is really the minimum standard that you should aim for.
So how do you know if your diamond is cut perfectly?
Your GIA or independent diamond certificate might say the diamond has an ‘excellent’ cut grade, but what does that really mean? Are all excellent cut grades the same? And are all excellent cut grades priced the same? The following sections take you through some of these issues.
Are all excellent cut grades the same?
I apologise in advance, but it’s time to get a bit technical here. The cut of a diamond is graded according to its percentages. For example, the top facet on a diamond is called a table facet. Diamonds with larger table facet percentages will look flat and lifeless, and I can honestly say they are diamonds I would never buy.
A perfectly cut diamond will usually have a table percentage of 56 to 57 per cent. However, according to a lot of diamond grading laboratories, a diamond can have up to a 61 per cent table percentage, and still be eligible to receive an excellent cut grade. Only a diamond cut specialist will be able to help you translate what the diamond certificate parameters really mean, and how they interact with each other and affect the brilliance and performance of the diamond.
If I told you a car had four wheels, a gear box and a steering wheel, would I have told you anything about the way the car drives? Diamonds are the same as cars in that way – so many minute characteristics all come together to produce the final performance.
Get a few of them wrong, and you are going to end up with something that looks like the real deal, but doesn’t perform like a well-oiled machine. After all, just like the saying, ‘Oils ain’t oils’. My expert tip is to try to choose your diamond with a table percentage of close to 57 per cent, a pavilion angle of 40.7, and a crown angle of 34.5 degrees.
Diamonds in the D to F range are the only diamonds considered to be in the truly white range. The reason for choosing diamonds in the D to F range is that the difference in colour grades is not linear. What this means is that the difference between an E and an F colour is not the same as the difference between an F and a G colour.
The lower you go in colour, the greater the difference in the visibly yellow tinge. If you are looking to maximise the best diamond for your budget, I recommend that the lowest colour you should accept is an F colour. D and E colours are great if that’s within the budget, but an F colour is the best way to still leverage all the other diamond characteristics to achieve the best performing white diamond.
The small increase in size you get by choosing a G-colour diamond is not worth the downgrade in colour from a white diamond to a yellow diamond. The average price difference in a 0.50ct diamond between an F and a G colour is only about $100. Most clients in my experience can see the difference between an F and a G colour when they are placed side by side.
By the way – and this is something you will be able to dazzle your friends with at your local trivia night – do you know why the colour grade starts at D and not A? The answer is that the original colour grading systems used to refer to diamonds as A-grade, B-grade and C-grade diamonds, in much the same way as pearls are graded. So when authorities introduced the new grading system, they wanted to make sure there wasn’t any confusion with the old criteria. That’s why the grading chart starts at D today.
The inclusions that you might see are:
- Graphite – type Inclusions – these show up as black spots
- Feathers – these look like a small semi-circle
- Crystals – these are essentially small crystalline inclusions that occurred in the stone at the time it was being formed.
- Clouds – these are a group or mist of minute inclusions that give a cloud-like appearance.
The Clarity Scale
The clarity scale ranges from FL (flawless), IF (internally flawless), VVS1-VVS2 (very, very small), VS1-VS2 (very small) to SI1-SI2 (small inclusions) and I1-I3 (included). The different denominations after the letter grade refer to whether your diamond is at the top or the bottom of a particular group. Basically what this means is that a SI1 is more like a VS2 stone than it is a I1. (See the following figure, showing the clarity grading scale, for the full clarity range.)
Here’s how the ratings break down in more detail:
FL and IF: This is really a minor distinction, and one that you would want to have verified by a proper microscope. Basically, the difference is just that the FL rating means there are no inclusions inside or on the surface of the stone, whereas the IF rating means the diamond is just internally flawless. While there will be a difference in the cost of the stone, the grading is really only a paper difference and not discernible to the naked eye.
VVS1-VVS2: A qualified diamond grader should be able to locate the inclusion in a stone with a VVS rating in anywhere from 30 seconds to a couple of minutes. When looking at a VVS stone, it is a good idea to use a 10× and a 20× loupe. Start off with the 10× loupe to see if you can locate the inclusion first, and then go up to the 20× to either confirm or continue looking. If you are not experienced with a loupe, it may take some practice to be able to focus. (See the breakout box ‘Holding the loupe’ for more information.)
VS1-VS2: The inclusion in a stone with this clarity grade should be becoming a little easier to see, depending on where the inclusion is in the stone. The best way to look for an inclusion here is to start in the centre of the stone. Then move to the outside edge of the diamond, beginning at 12 o’clock and moving clockwise around the stone.
SI1-SI2: As you move down the clarity grade, the distinctions between the types of inclusions should be a lot easier to identify. While an SI1 stone is usually quite pleasant, most people today should be able to identify an SI2 stone straightaway. Sometimes if the inclusion is big enough or in the centre, you can even see it without a magnifying glass.
SI3: Beware of anyone claiming to have an SI3 clarity graded diamond. This is not a recognised clarity grade, and is basically just a nice way of saying that it is a really good I1. These diamonds will never come with an international diamond certificate and are much cheaper than an SI2. Make sure that you inspect this kind of stone very carefully with a loupe. While heavily included diamonds might be cheap now, if you ever want to trade up the diamond in the future, it will be very difficult to get a high trade-in figure.
I1-I3: This clarity grade is really at the bottom of the barrel, and verging on looking like smashed glass. You should really try to avoid this grade if you can help it. All the extra inclusions inside the stone interfere with the light as it travels through your diamond, causing it to sparkle significantly less. The only client this diamond is really suited for is the person who wants size over everything else.
Carat weight refers to the actual weight of the stone (one carat= 0.2 grams) and this doesn’t always relate to the physical size or diameter you see. As a diamond increases in weight, it also increases in volume in every direction. So some of the increase or decrease in diamond weight will be seen in the diameter and some will be in the depth. If the stone is poorly cut, it will have more of the weight in the depth and so have a smaller diameter.
For example, a poorly or averagely cut one-carat diamond can have the same diameter as a 0.90ct perfectly cut diamond. Not only will the one-carat diamond look the same size as the perfectly cut 0.90ct diamond, but it will also sparkle significantly less. Ultimately, the larger stone has lost its brilliance because light is being lost through the back of the stone.
This situation is quite common for discount and chain stores, because they think clients will only focus on the weight of the diamond and not its diameter (or physical size). Always choose a diamond that has the correct diameter for its weight. A 1.00ct diamond, for example, should measure 6.5mm in diameter, and a 0.50ct diamond should measure 5.1mm in diameter.