What kind of labels are these, then? Many colours have already been discovered and there are pink to red and blue to green diamonds. Each colour also has its own gradations in vibrancy, making almost every conceivable colour possible.
How do diamonds with fantasy colours get their colour?
The fantasy colours of diamonds are again created by the surrounding elements. Many colours can be traced back to certain components and/or chemicals that are present during growth. Below you will find some examples of popular fantasy colours.
Red diamonds: Pure Carbon with a deformed crystal structure to create a red tint.
Green diamonds: A layer around the diamond, which was created by natural radiation from nearby rocks.
Blue diamonds: A low level of nitrogen and a high content of Boron or Nickel.
Black diamonds: Actually colorless diamonds with pieces of rock or stone, creating black.
How is the colour of a diamond determined?
Many diamond colours, many personal preferences and a worldwide distribution certainly do not make it easy to compare diamonds by colour. Here too, the GIA came up with a plan and around 1950 created a system that is currently used by the entire industry. This scale is also often found in the official certificate of a diamond, so that subjective terms such as ‘blue-white’ and AAAA are set aside.
Global colour scale for “white” diamonds
As mentioned above, the scale within this segment starts at D (colourless) and goes up to Z (yellowish-brown). Why D? Because the GIA wanted a fresh start and older grades were sometimes known as BBB or 4. To avoid confusion they therefore started further in the alphabet.
From D to Z means 23 different gradations and does not always communicate easily. For this purpose some letters have been combined into a group with a more descriptive name. These are colourless (D-F); almost colourless (G-j); weak (K-M); very light (N-R); and light (S-Z).
diamond colour grading scale
To see what colour a stone has, a set of so-called ‘master stones’ is used to look at each stone the diamond in question matches. If the colour of the diamond – under special lighting and precise conditions – corresponds to a master stone, then the gradation is officially assigned.
Global colour scale for fantasy coloured diamonds
Many fantasy coloured diamonds are unsuitable for jewellery or lose value because their colour is not vibrant enough. For this purpose, these diamonds look at the hue and saturation in terms of color. Another factor is that the colour must be visible on the table side of the diamond.
There are no master stones for fantasy colours and the assessment is very precise work. The color determination is done by lab technicians with years of training and specialization in this field.
How does colour influence the value of a diamond?
You now know that there are two decisive groups that can determine the value (if one looks at the diamond colour). The diamond is labelled as a “white” diamond or as a fantasy colour. The next logical step is to see what each colour is worth.
The value of “white” diamonds
The purest form of diamond is completely transparent. Light can thus pass through the gem without being slowed down, causing the ‘fire’ through reflections. These diamonds are the rarest in this group and therefore the most valuable.
To give you an idea of their value. One of the largest diamonds with D-color quality is the Millennium Star. This diamond is one of the most beautiful of its kind.