Email Alerts Contact ABOUT US OUR OPERATIONS OUR INDUSTRY SUSTAINABILITY INVESTORS MEDIA CAREERS Home / Our Industry / About Diamonds / Coloured Diamonds Coloured Diamonds Fancy colour diamonds are the Earth’s rarest and most valuable gemstones Nature produces diamonds in every imaginable colour, with over 300 shades and hues having been identified to date. However, it is estimated that only one in 10,000 diamonds has a ‘fancy colour’. The premium prices commanded by ‘fancy coloured’ diamonds are dependent on their tone, saturation and distribution of colour. A diamond usually comprises more than 99.7% carbon, but the remaining 0.3 per cent constitutes traces of impurities of other elements during its formation. A diamond’s colour is generally determined by such chemical impurities, but it can also be caused by a distortion of the crystal lattice. The known causes of coloured diamonds are as follows: Blue: boron Pink, purple, red and some brown: deformation of the crystal lattice Yellow, brown (champagne) and orange: nitrogen Violet: hydrogen Green: exposure to gamma rays deep within the surface of the earth Black, grey: graphites or sulphides and are often composed of many small diamonds intimately inter-grown with one another Coloured diamonds require different considerations to colourless stones when determining their value. The hue of coloured diamonds is graded in two ways. The first factor considered is the stone’s basic colour, i.e. blue, pink, yellow etc. The second factor is the colour’s intensity; usually the more intense the colour, the rarer and more expensive a diamond will be. The intensity of the colour saturation grade ranges from ‘faint’ to ‘fancy vivid’ (see chart on right). Blue diamonds Pink diamonds Yellow diamonds Champagne/Cognac diamonds Orange diamonds Green diamonds Red diamonds COLOUR HUES Read more on the GIA website COLOUR STRENGTH FOLLOW US Join the conversation on our social media channels linkedin twitter facebook instagram Site map rss Contact Disclaimer Accessibility Privacy Cookies Policy Email Alerts © Petra Diamonds Limited