4Cs OF DIAMONDS
A diamond is a salute to the precious moments in our lives, a dazzling reminder of someone’s love, a reward for a great accomplishment and an enduring symbol to be treasured and celebrated
CHOOSING THE RIGHT DIAMOND
Diamonds are graded using a universal system that assesses the stone on its colour, clarity, cut and carat-weight, commonly known as the ‘Four Cs’. Every diamond, no matter how large or small, has a set of unique characteristics that determine its value.
A diamond’s cut is not just a description of its shape, it is the most important factor in determining its fire, brilliance and scintillation. While nature determines the colour, clarity and carat of a stone, the cut is in the hands of the master diamond cutter.
Essentially, the cut of a diamond determines how effectively light that enters the stone is refracted within and reflected back through the top of the diamond. Factors such as proportion, symmetry and polish affect the quality of the diamond: the closer they are to perfect, the better the diamond will perform in terms of fire, brilliance and scintillation.
A diamond cut to ideal proportion and symmetry will reflect the perfect balance of light back through the top of the stone, while a poorly cut diamond will result in a loss of light, and hence sparkle, through the sides and bottom.
Colour refers to the presence or absence of a yellow or brown tint in white diamonds. The closer a diamond is to colourless, the more rare and valuable it is.
Most diamonds appear colourless to an untrained eye, yet many have slight tones of yellow or brown which affect its value. (The exception to this is fancy-coloured diamonds, such as deep yellows, pinks and blues, which lie outside the white diamond colour range.)
The colour of a diamond is measured on an alphabetical scale starting from D (colourless). Each letter grade has a clearly defined range of colour appearance that determines its value, and as you move down the scale, the colour tint in the diamond increases.
|D:||Absolutely colourless. The most rare and most valuable. Less than 1% of diamond’s mined worldwide are graded as colour D.|
|E – F:||Also considered colourless, even though it is a minimal trace of colour that can only be detected by an expert gemmologist. Less rare than D, and more valuable than G – H.|
|G – H:||Near colourless. To the eye these diamonds appear clear and colourless, although they also contain minute traces of colour. Less rare than E – F, but more valuable than I – J.|
|I – J:||Near colourless with a faint tint of yellow not easily identified by the eye. Less rare than G – H, but more valuable than K – L.|
|K – L:||Faint yellow tint, visible to the eye. Less rare than I – J, but slightly more valuable than M – N.|
|M – Z:||Very light yellow, easily identified by the eye. Least valuable of the diamond colour grade.|
|Fancy Yellow:||More rare and more valuable than the colourless and near colourless white diamonds. These diamonds contain nitrogen which results in a yellow appearance. The more yellow the diamond is, the more rare and more valuable it is. Yellow diamonds are graded Light Fancy Yellow, Fancy Yellow, and Intense Fancy Yellow.|
Fluorescence refers to the degree of luminescence exhibited in certain diamonds when exposed to ultraviolet light or strong sunlight. Most commonly, diamonds display a blue fluorescence, but can also appear in a variety of colours. Faint to medium fluorescence is rarely detected under ordinary lighting conditions. Strong or very strong fluorescence may make a diamond appear ‘milky’ or ‘oily’.
Fluorescence is not always a bad thing as blue fluorescence may enhance the colour of a diamond. For example, a diamond graded H with blue fluorescence may appear whiter than it really is. Fluorescence can also hide a slight yellow tint in diamonds graded I, J and K.
Fluorescence is indicated on a GIA diamond certificate and measured in Faint, Medium or Strong.
To learn more about fluorescence in diamonds, read our blog post.
Clarity measures the incidence of natural inclusions or imperfections found in a diamond. The closer a diamond is to flawless, i.e.: no inclusions visible through a jewellers loupe, the more rare it is and the greater its value. Most inclusions are not visible to the naked eye, so diamonds are examined under a 10x magnifying loupe to determine their clarity.
Clarity characteristics are usually divided into two categories:
- Inclusions: imperfections that occur naturally inside the diamond itself. These were formed miles below the surface, when the diamond was formed under intense heat and pressure.
- Blemishes: imperfections that occur on the surface of the diamond and occur during the cutting and polishing process.
A diamond’s clarity is determined by the number, size, type and placement of the inclusions, such as tiny white points, dark dots, or feathery cracks naturally found in the diamond. A diamond’s clarity is unique and acts as a fingerprint. When choosing a diamond, you should select a clarity grade in which the inclusions are not visible without magnification. In other words, we recommend diamonds with a clarity grade of SI2 and up.
DIAMOND CLARITY SCALE:
|F (Flawless):||No inclusions or blemishes visible to a skilled gemmologist under a 10x magnification loupe.|
|IF (Internally Flawless):||No visible inclusions under a 10x magnification loupe, insignificant surface blemishes.|
|VVS1 – VVS2 (Very Very Slight Inclusions):||Minute inclusions so small they are hardly visible under a 10x magnification loupe. Not visible to the naked eye.|
|VS1 – VS2 (Very Slight Inclusions):||Minor inclusions that are visible under a 10x magnification loupe. Not visible to the naked eye.|
|SI1 – SI2
|Noticeable inclusions seen under a 10x magnification loupe. Not visible to the naked eye.|
|I1 – I2 – I3 (Included):||Inclusions are large and noticeable to the naked eye. For this reason, Shimansky carries only FL to SI clarity diamonds.|
Carat refers to the weight of a diamond and other gemstones. A carat is a unit of measurement equal to 0.2gm or 200mg. In the diamond industry, size does count. Large diamonds are rarely found in nature making them more valuable than smaller diamonds of the same colour and clarity.
This means that the price of a diamond will increase exponentially as the carat size of the diamond increases. Beware that the size or carat weight of a diamond alone cannot be used to determine its value. Factors such as colour and clarity should also be considered. A large diamond with a low colour and clarity will be less valuable than a smaller diamond with a high colour and clarity.
Another common misconception is that a 2 carat diamond will look twice the size of a 1 carat diamond. As the carat weight of a diamond is measured in mass and not physical size, a 2 carat diamond will not be twice the size of a 1.00 carat diamond but it will be twice the weight.