Since 1998, the Aurora Pyramid of Hope has housed and displayed a collection of 296 natural diamonds in a wide variety of colours, and since 2005, it can be seen in the Natural History Museum of London.
It’s easy to forget that diamonds are rare, natural occurrences that make a long journey from their hot, high pressure environments under the surface of the earth. And, what many may not know about this very precious and rare mineral compound is that it begins its formation 1 to 3 billion years before it sees the light of day.
Diamonds form in the mantle, or the upper crust, of the earth in pockets of lava and make their way to the surface of the planet via volcanic eruptions. That is, before we started digging for them.
What colours can diamonds be?
There are a variety of diamond colours that can form naturally and various shades of each colour. White, blue, yellow, orange, red, green, pink, purple, grey and black diamonds are all naturally occurring, with different variations of each on the colour spectrum.
Of all the coloured diamonds, the rarest diamond colour is the red diamond. These are found mostly in Africa, Australia and Brazil, and there are only around twenty or thirty true red diamonds known to exist and most measure in at less than half a carat.
How do diamonds get their colour?
Coloured diamonds contain interstitial impurities or defects in their atomic structures that cause their coloration.
Their colour and formation is affected by minerals and chemicals in their immediate surroundings, meaning no two diamonds are the same. This also means that it is almost impossible to have a definitive list of diamond colours, because the hues and shades they present themselves in are infinite.
A diamond with no colour is chemically pure and structurally perfect meaning the rarest diamond colour is a large, white, flawless diamond. But what the rarest white diamonds and the rarest of the coloured diamonds – that is, the red diamond – have in common, is that they are both made purely from carbon.
What’s the most expensive diamond colour?
Diamonds that are slightly more yellow than white are less valuable than a pure white diamond. As mentioned, the brilliance of a diamond is reduced by the presence of impurities and structural defects and, depending on the hue and intensity of a diamond’s coloration, a diamond’s colour can either detract from or enhance its value.
Colour, clarity, carat and cut – the 4C’s that determine the value of a diamond
Because there are so many shades, structural variations, and ways of cutting diamonds, it only makes sense that we have a system for measuring and determining the value of each. This system is referred to as the 4Cs and it consists of:
- Colour – The most colourless diamonds are the most desirable and highest rated colour grade, D. And after the red diamond, this is also the most highly valued and most expensive diamond colour.
- Clarity – The clearer the diamond, or the fewer the number of inclusions a diamond has, the higher its value.
- Carat – Diamonds are measured in carats, which indicates their weight rather than their size. Larger carat weights are rarer and therefore more valuable than smaller ones.
- Cut – A diamond’s cut is the most important factor in its value. The cut of the diamond affects its brilliance and the way it disperses light more than any other element of its structure.
Hopefully this short but comprehensive guide to coloured diamonds has broadened your knowledge on these impressive gemstones, but if there’s anything else you want to know, don’t hesitate to get in touch with us.