Loose Diamonds/Diamond Jewellery
Before you select and buy a diamond, it is advisable to learn about this fascinating gemstone, so that you understand which features contribute to its lasting beauty and value. While each diamond is a unique, natural treasure, all diamonds share certain attributes that allow their comparison and evaluation. These features are commonly know as the 4Cs
Colour, Clarity, Cut and Carat Weight.
The cut of a diamond is defined by the number, exact shape and alignment of its facets; and therefore the cut also determines how well the diamond can perform. The performance is measured by the efficiency by which the diamond can reflect light back to the observer’s eye. Independent of its clarity and colour, a diamond with a good cut will be very lively and display brilliance and fire, whereas a lesser well-cut stone might appear dark and dull. Another advantage of well-cut diamonds is, that they appear larger than those of the same carat weight that have a less precise cut. The best return of light and brilliance is achieved when the cut of the diamond is neither too deep, nor to shallow.
Ideal Cut Diamonds
An ideal cut diamond is a round brilliant cut or square princess cut diamond that is cut to very exact proportions within very tight size tolerances and features perfect symmetry, finish and polish. Due to the “perfect” cut, brilliance, fire and scintillation of the diamond are optimized making this diamond stand out by its beauty and lively sparkle. A special sub category of ideal cut diamonds are the Hearts and Arrow diamonds.
Heart and Arrow Cuts
Hearts and Arrow cuts are round brilliant cut diamonds that are cut to very precise tolerances. When looking at these diamonds from the table down, one can see a radial aligned pattern of arrows, whereas one can see 8 hearts that are placed within small “V”-shapes when looking at the diamond from the pavilion up. Since these diamonds are cut to exacting standards, they reflect and refract light to the fullest extent possible and hence are the best performing diamonds in the market.
Brilliance, Dispersion and Scintillation define a Diamonds Beauty
A diamond’s beauty is defined by how well it reflects and refracts light. There are three different properties present in a well-cut diamond, that define its performance: Brilliance, scintillation and dispersion.
Brilliance is essentially light that enters a diamond and that gets nearly entirely reflected.
When a light ray enters a diamond and gets broken into the spectrum colours, then the resulting phenomenon is called dispersion or “fire”.
Scintillation can be described as flashes of reflected light emanating from a diamond’s polished facets that are observed when either the diamond, or light source, or the onlooker is moving. Scintillation is often referred to as “sparkle”.
The colour of a white diamond is graded on a scale from D-Z; D representing the colourless side of the scale, whereas Z marks the end point of the light yellow colour range. The scale is subdivided into five main groups:
D-F representing the colourless range:
Diamonds in this colour range are the most rare and most thought-after on the colour scale. D and E colour diamonds are colourless whereas F colour diamonds display a very faint trace of colour when viewed by a gemologist face down. Diamonds in the colourless range benefit from being set in white gold or platinum, since the white metal colour promotes the whiteness of the diamond; whereas when set in yellow gold the diamond would look more yellow than it actually is.
G-J representing the near colourless range:
Diamonds in this colour range look colourless when viewed from top, but display a minute amount of colour when inspected against a white background in the face down position. The colour is not noticeable for an untrained observer once the diamond is placed into its setting. In terms of value for money, near colourless diamonds represent a great value proposition.
K-M representing the faint yellow range:
Diamonds in this colour range might display a slight amount of colour, if the diamond is viewed in the face up position. In the face-down position a faint colour is visiblen even to the untrained onlooker. These diamonds are best set in yellow gold, since the colour of the gold reflected into the diamonds and the diamond’s own body colour are a good match. The predominant body colour of white diamonds is yellow, however some diamonds take on a brown colour hint, which is a result of structure related, internal graining in combination with trace elements of nitrogen.
N-R representing the very light yellow range
Tanishq doesn’t promote diamonds in this colour range.
S-Z representing the light yellow range
Tanishq doesn’t promote diamonds in this colour range.
Natural diamonds are the result of carbon exposed to immense pressure and heat deep in the core of the earth. The formation process can result in a variety of internal characteristics called 'inclusions' and external characteristics called 'blemishes.' Inclusions and blemishes are referred to as ‘clarity characteristics’ and the evaluation of diamonds for clarity is standardized at 10 power magnification; meaning that the described clarity characteristics can only be observed when the diamond is view with a 10 x loupe or eye glass.
While most diamonds are not perfectly pure, the closer they come, the higher is their value. Clarity is an important value factor for a diamond, because the size, number and location of clarity characteristics impact the durability of the diamond. Even though a diamond is the hardest material on earth, it is not unbreakable. If for instance a surface-reaching feather is present in a diamond, a hard knock might cleave the diamond.
Clarity grades are divided into 6 main categories:
- Flawless (FL)
No inclusions and no blemishes visible under 10x magnification
- Internally Flawless (IF)
No inclusions visible under 10x magnification
- Very, Very Slightly Included (VVS1 and VVS2)
Inclusions so slight they are difficult for a skilled grader to see under 10x magnification
- Very Slightly Included (VS1 and VS2)
Inclusions are observed with effort under 10x magnification, but can be characterized as minor
- Slightly Included (SI1 and SI2)
Inclusions are noticeable under 10x magnification
- Included (I1, I2, and I3)
Inclusions are obvious under 10x magnification, which may affect transparency and brilliance
To make sure that no clarity characteristics are “eye-visible” it is advisable to select a diamond in the VS2 clarity range or higher.
Diamonds in the SI clarity range represent a great value, if the inclusion or the clarity characteristic that is present in the diamond is in an area that is covered by the setting. It is advisable to balance your preferred clarity range with a suitable colour range. Commonly diamonds in the VS2 or higher clarity range are paired with D-F colour range diamonds, whereas SI clarity diamonds create a good value proposition when combined with a G-I colour range stone.
Most blemishes and inclusions are too small to be noticed by anyone other than a trained diamond expert. To the un-aided eye (without an eye glass), a VS and an SI diamond may look the same, but actually these diamonds are vastly different in terms of overall quality and associated value. For this reason a precise assessment of a diamond's clarity by an expert diamond grader is very important.
However, diamonds come also in other colours than white, these so called fancy colour diamonds are very rare. The colour of a yellow diamond is caused by trace elements of nitrogen that were present in the atmosphere when the diamond was formed. Other fancy colour diamonds include green, pink, red, green and blue.
When comparing diamond colours; as a general rule, it is recommended to look at two diamonds that are at least two colour grades apart, so that it is even possible to discern a colour difference. Also, when looking at diamonds in the face up position, it is very difficult to make out any colour difference and the colour is best noticeable from the side view.
Diamond Carat Weight
Carat (with a “C”) is a measure of the weight for precious stones. One carat equals 0.20 grams. In early days of trading gemstones the dried seeds of the Carob tree were used as a standard measure of weight for diamonds and gemstones and the origin of the word “carat” can be traced back to “carob”.
In the process of cutting rough diamonds, up to 2/3 of the weight gets lost to achieve the desired shape and cut of the finished polished diamond. Considering the cutting losses and the fact that large pieces of rough in high quality are unearthed much less often than small rough diamonds, it becomes evident why for instance one 2 carat diamond costs a lot more than two 1 carat diamonds of the same quality.
When relating to the size of round diamonds, the dimension measured to establish a size to weight ratio is the diameter of the diamond. For instance, the size of a reasonably well proportioned 1 carat diamond is approximately 6.5mm. However, this doesn’t mean that a 2 carat diamond measures 13mm, (but only 8.2mm in actuality) because much of the diamond weight is attributed to the depth of the diamond.
What is the right diamond size for me?
The choice of your diamond will be guided not only by considerations of the size, but also of the available budget. When a “bigger look” is preferred, then maybe a different diamond shape than round will provide a better size to weight ratio. For instance, marquise cut diamonds have a shallow pavilion and since less of the diamond weight is attributes to the depth of the stone, a one carat marquise cut diamond looks larger than a one carat round brilliant cut diamond. Naturally, other quality considerations, such as the colour and clarity of the diamond will also guide your selection and although the carat weight is an important influencing factor for the price, it is not the only one.