Diamonds are found in a variety of colours. The rarest diamonds are ones that have a colourless grading or diamonds with fancy colours such as greens, blues, reds and pinks.
GIA Gemological Institute of America pioneered the universal colour grading system for diamonds in the early 1940’s to overcome all the confusing colour grading systems in use. The GIA colour grading classification starts from D, the finest colour grade (colourless), and continues through the alphabet to Z becoming progressively more tinted to yellow.
A set of master comparison stones calibrated to the exact colour of every colour grade is the most reliable method of grading diamonds for colour. This allows for the accurate colour grading of the diamond.
Grading polished diamonds for colour means determing the amount that the diamond’s “body colour” deviates from the whitest possible (water like colourless) colour. This concept should not be confused with the sparkle, brilliance, or scintillation of the diamond. Because diamonds have a high brilliance and dispersion of light, the colour grade cannot be accurately determined by looking at the stone from the top (face up) position. It is best to observe colour by examining the stone through the side of the pavilion (bottom of the stone) with the diamond upside down in a white grading trough.
Diamonds that are colour graded in the D-F range are the rarest and consequently most valuable. In reality, diamonds in the G-J range have such a small amount of colour that the untrained eye can not see it and as such offer great value.
Diamonds that occur by rare accidents of nature in shades of pink, blue, green, amber, or even red are known as fancy coloured diamonds and are evaluated by a different set of colour grading standards. These standards take into consideration various factors such as hue and saturation. Fancy coloured diamonds are expensive because of their extreme rarity and colour.
Diamond colour has a significant impact on its value. The colour scale ranges from D to Z, from colourless to light yellow, respectively. The further from colourless that a diamond is grade, the less rare and therefore less valuable it becomes. When buying a diamond, take into consideration that it is often very difficult to detect the difference between a colourless diamond (D-F) and a near colourless diamond (G-J), especially when it is mounted in jewellery.
Diamonds with a K-Z colour grade usually have yellow shading that can be detected by the naked eye. A well cut diamond with good proportions in a lower colour grade will still release the brilliance and fire of a diamond in a higher colour grade, dispersing light in such a way that diamonds with a lower colour grade are still extremely attractive and look beautiful in jewellery. The colour of a diamond is not the only deciding factor to determine the value, there is a combination of qualities including cut, clarity, carat weight and the shape of the diamond that all help to determine and influence the value of the diamond.
Diamonds with a higher colour grade, appear whiter. The whiter the diamond, more light is able to pass through it, making it sparkle and shine. Diamonds with a colour grade of J and higher are near-colourless or colourless, and are recommend best value, since their colour is undetectable to the untrained and unaided eye.
The grades D, E, F are exceptionally fine white diamonds being the only grades referred to as colourless. E colour diamonds are extremely close to D colour diamonds, however the colour variance can only be detected in a controlled diamond grading environment. The variance in price per carat between a D and E colour diamond is significant at the wholesale level reflecting the rarity of these diamonds in the market.
Even though the most valuable diamond is D colour, a diamond which grades G through J will appear nearly colourless. Sometimes a jeweller will speak of how diamonds “face up” to the eye, referring to the fact that diamonds are graded for colour from bottom of the stone and therefore give the illusion of less body colour from the top because facets on the diamond disperse spectral colors to the eye.
Diamond Imports
