Rare Coloured Diamonds

Rare Coloured Diamonds

Written by on 10 January 2011

Everyone I work with knows my absolute love for anything that catches the light and sparkles and here in the office is common knowledge that I have a certain love for pink, so what better than to see such a gorgeous pink engagement ring being auctioned off back in November 2010, and straight away was a huge interest to me.

Such a large and rare Gemstone became known back in November when it was displayed at an auction in Sotherbys in Geneva in Switzerland. Such a gorgeous gemstone raised a huge interest at the time and was estimated to reach anywhere between 17 million and 24 million, this would be potentially the most paid for gemstone. The stone in total weights 24.78cts and is cut in what is known as an emerald cut, the diamond sits in a silver setting flanked by two triangular shaped diamonds either side.

The auction took place on the 16th November 2010 where four bidders watched closely as the gemstone rapidly increased in price. The final bid went to a well known British billionaire names Lawrence Graff and was purchased for 29 million, soon after his purchased it was then named after the ‘Graff pink’ This stone has now hit the record for one of the most valuable coloured diamonds to date followed closely by the blue diamond named the wittelsbach which was own previously by a 17th Century Spanish king which was also sold to Graff for 16.3 million back in December 2008.

The stone being an emerald cut pink diamond has been displayed in a flat claw setting which means all angles of the stone are clearly visible, seeing the gemstone in this particular cut also enhances its rariety. The pink diamond has been classed as an unusual intensive pink colour by the Gemmological institute and has said to possibly be in the world’s top 2% of flawless diamonds once the gemstone has been re-polished. This intensively pink in colour is created by a form of distortion found around the area of where the stone has been created which shows the display of light in the way this stone does.

Dark Yellow Coloured Diamond

Before the diamond was widely know at this auction it was displayed in Hong kong and was toured around the world before the auction took place. One of the know owners before Graff around 60 years ago was a famous jeweller to the stars named Harry Winston. Harry Winston is one of the most famous jewellers for the stars and originally starting renting out his jewellery for the Oscars from his shop in the 1920’s, and was also referenced to in the Marilyn Munroe’s 1953 gentlemen prefer blondes she delivers the line 'Talk to me Harry Winston, tell me all about it.'

All natural coloured diamonds are extremely rare and due to this do come with a high price tag, it is said that this diamond will now be in the category of one of the top ten most desirable and valuable diamonds in the world, alongside the priceless Koh-i-Noor, the hope diamond priced at £220 million and the Steinmetz Pink valued at £16 million.

Pressure Treated Coloured Diamond

All natural coloured diamond are highly rare and costly and we do find we have a great interest to such wonderful gemstones here at our studio at Harriet Kelsall Jewellery Design. We are increasingly using these wonderful coloured diamonds which have been heat and pressure treated, this is an additional process which is applied to a white diamond which speeds up the process of what a natural coloured diamond would go through throughout thousands of years under the ground, due to this process these coloured diamonds are more accessible and certainly come with a lower price tag, so a realistic option for your bespoke engagement ring.

Most diamonds are formed in the earth’s crust and are under a constant high temperature and the depths of the earth’s crust around 140 to 190 kilometers. The carbon minerals are evident within these depths which will have continued growing since the age of the earth. It is when a volcanic eruption forms and magma cools into igneous rocks nearer the earth’s surface. With these, unusual shades found such as blue, yellow, orange, red, green, pink brown and black are found. Coloured diamonds will be found with impurities of structural defects which will commonly cause such colouration within this gemstone. The most know impurity within these coloured diamonds nitrogen is evident which will cause a yellow colour to a diamond.

The higher value coloured diamond will tend to be the pink and the blue which tend to be found in a paler colour the deeper in colour the diamond is the increase of value become more significant. The intense yellow tinted diamond is graded as one of the fancy colours rather than a lower quality diamond, this arrays much more of a canary yellow in look