About Jools | About Diamonds | About South Sea Pearls | Pearl Sorting and Grading
The first step to know the basics of buying a diamond is to learn about cut, colour, clarity and carat. These are also known as the "Four Cs". Cut, Clarity, Colour and Carat Weight.
CUT
The cut gives each diamond its unique sparkle and brilliance by allowing the maximum amount of light to enter and reflect back out of the diamond.
An understanding of diamond cut begins with the shape of a diamond. The standard round brilliant is the shape used in most diamond jewellery. All others are known as fancy shapes. Traditional fancy shapes include the Princess, Marquise, Pear, Oval and Emerald cuts. Hearts, cushions, Asscher and a variety of others are also gaining popularity in diamond jewellery.
Cut is given priority over Clarity, Colour and Carat Weight; however it takes an experienced eye to see the difference between a well proportioned diamond and a poorly cut stone. This why you should choose your retailer before you choose your diamond.
The illustrations below show how this happens and why an Ideal Cut or Fine Cut diamond is brighter and more valuable than a Shallow Cut or Deep Cut stone, but to the casual observer this difference is not always immediately apparent.
CLARITY
Diamond clarity refers to the absence of these internal or external inclusions and blemishes that can be likened to birthmarks. Diamonds without these birthmarks are rare, and rarity affects a diamond’s value.
Every diamond is unique. None is absolutely perfect under 10× magnification, though some come close. Known as Flawless diamonds, these are exceptionally rare and most jewellers have never seen one. They use this grading system to determine the rarity of a diamond:
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F – Flawless:
No internal or external flaws. Very rare. -
IF – Internally Flawless:
No internal flaws, but some surface flaws. Very rare. -
VVS1 – VVS2:
Very Very Slightly Included (two grades). Minute inclusions very difficult to detect under 10x magnification by a trained gemologist. -
VS1 – VS2:
Very Slightly Included (two grades). Minute inclusions that are also very difficult to detect under 10x magnification by a trained gemologist. -
SI1 – SI2:
Slightly Included (two grades). Minute inclusions more easily detected under 10x magnification. -
I1 – I2 – I3:
Included (three grades). Inclusions visible under 10x magnification as well as to the human eye. These diamonds are typically used in ‘cheap’ or ‘bargain’ jewellery.
COLOUR
Pure white is generally defined as the absence of colour and this is what most people look for in a diamond. The clearer the stone, the more light passes through it allowing it to sparkle more.
Diamond colour is all about what you can’t see. Diamonds are valued using a simple concept – the less colour, the higher their value. The exception to this is fancy-colour diamonds, such as pinks and blues, which lie outside this colour range.
HRD, GIA and IGI use an internationally accepted system for grading diamonds according to the purity of their colour.
The scale begins with the letter D, representing colourless, and continues with increasing presence of colour to the letter Z, or near-colourless. Each letter grade has a clearly defined range of colour appearance. Diamonds are colour-graded by comparing them to stones of known colour under controlled lighting and precise viewing conditions.
The scale starts with D being the highest standard for a colourless stone and travels downwards through the alphabet to take into account stones with faint or light traces of yellow.
- Diamonds that are graded D to F are extremely rare.
- Diamonds graded G to I show almost no colour to an untrained eye.
- Diamonds graded J to L contain faint traces of yellow and so on.
DEF: Colourless
GHI: Near Colourless
JKL: Faint Yellow
MNO: Very Light Yellow
PQR: Light Yellow
Many of these colour distinctions are so subtle as to be invisible to the untrained eye. But these slight differences make a very big difference in diamond quality and price.
CARAT WEIGHT
Diamonds and other gemstones are weighed in metric carats: one carat is equal to 0.2 grams, about the same weight as a paperclip. The word ‘carat’ is taken from the carob seeds that were used to balance scales in ancient times, but it is not to be confused with the word ‘karat’, which is the method for determining the purity of gold (as in ‘18K gold’).
Carat refers to the unit of weight by which a diamond is measured, and because larger diamonds are rarer than their smaller counterparts, the cost of a diamond will usually rise in exponential increments according to its size. But two diamonds of equal weight can have very different values depending on the other attributes of Cut, Clarity and Colour.
It is the combination of these characteristics that determines the individual value of every stone, which is why an authentic GIA certificate or Auscert is so essential to your purchasing consideration.
To find the best Diamond that fits within your price range it essentially comes down to a compromise between the 4Cs and your consideration of which factors are most important to you. You may choose a larger lower colour diamond or prefer a smaller high colour, cut and clarity diamond.
You may for example choose a 75 point diamond in a high colour F collection colour and a slightly lower SI1 clarity. This means that you have a relatively large diamond with a very good colour and which to the naked eye does not have any inclusions. On the other hand, having a diamond that has as few inclusions as possible may be important to you (even if you need a microscope to see the inclusions); in that case you may choose a high VVs or Vs clarity, a good colour G and a smaller diamond carat weight. Once you know how diamond grading works, it's just a matter for you to decide what is best for you.
Your diamond is a store of value that can grow more precious with time. This is an important reason for buying the best quality stone you can, regardless of size or the design of the piece of jewellery. We assure you that at Jools, you will not only be able to find the diamond that you are looking for, you will also be able to have your very own design made into reality by our in-house designer.
Pink Diamonds
Western Australia is home to one of the most rare and sought-after diamonds in the world – Pink Diamonds. The Argyle Pink Diamond mine is the world’s primary source of pink diamonds which attract 20 times the amount of an equivalent white diamond.
When buying a pink diamond, it is important to consider the “4Cs” as you would with white diamonds, with the exception of Colour. Coloured diamonds fall beyond the Z grading and are assigned descriptive names such as ‘fancy intense pink’ and ‘fancy vivid purplish pink’. An intense coloured stone is of much greater value than a D colourless diamond due to its relative scarcity.
Cognac Diamonds
Cognac, or Champagne, diamonds are naturally coloured diamonds that can also be found in the Argyle mine. They can be found in a wide range of colours ranging from a light straw to a rich cognac.
The grading system is very similar to that of pink diamonds, in that the 4Cs of colour, cut, clarity and carat weight do not apply. Argyle Diamonds created a scale specifically for cognac diamonds. They are graded on a C1-C7 colour scale. C1 and C2 represent light champagne, C3 and C4 medium champagne and C5 and C6 dark champagne. The highest grading of C7 is given to the fancy cognac.
