Diamonds come in different shades of colour and can range from colourless to varying shades of yellow. Even though most diamonds appear colourless to an untrained eye, many have slight tones of yellow or brown that affect its value. The closer a diamond is to colourless, the more rare and valuable it is.
White or colourless diamonds are graded on a colour scale from D (colourless) to Z (heavily tinted yellow). A universally-accepted and standardised colour grading system, it has been accepted since the 1950s. This grading is done in a special, controlled environment because the difference between each shade is very subtle and often not noticeable to the untrained eye.
D: Absolutely colourless. The most rare and valuable. Less than 1% of diamonds 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 naked 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. Less rare than G – H, but more valuable than K – L.
K - L: A faint yellow tint that is visible to the eye. Less rare than I – J, but slightly more valuable than M – N.
M – Z: A very light yellow tint, easily identified by the eye. Least valuable of the diamond colour grade.
Strength: The strength of fluorescence varies from none, faint and medium to strong and very strong. Though some diamonds have very strong fluorescence and appear dull or cloudy even in regular lighting conditions, the majority of diamonds do not have a widely notable fluorescent appearance when looked at with an untrained eye.
Fluorescence affects the value of a diamond depending on its colour and strength. If there is a strong yellow fluorescence present, it may decrease the value of the diamond, while the presence of blue fluorescence may increase the value of a diamond that does not have a high colour grading (and thus has a yellowish tint).
Diamonds certified by the GIA or EGL clearly state on their Certificates of Authenticity whether there is a presence of fluorescence. If the diamond does not have fluorescence, it will be marked as “none,” and if fluorescence is present, it will be noted as either “faint,” “medium,” “strong” or “very strong.”
Because fluorescence is a natural phenomenon, it cannot be judged in isolation. Each diamond is unique, and fluorescence thus affects it in a unique way. When shopping for a diamond, always be sure to look at its unique characteristics and qualities and make sure you understand the grading on its certificate.
The true value of a Shimansky jewellery creation is only realised when it is worn by the person it is meant for.