February 2011 - Andrew Geoghegan

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Everything you need to know about Yellow Diamonds

 


Rarity is one reason for the desirability of yellow diamonds but Tiffany also had a part to play. In 1878, after a year of being studied, a rough yellow diamond was cut under the supervision of a brilliant gemmologist George Kunz. This exquisite stone yielded an impressive 128.51 carat cushion cut and was to be become the emblem of Tiffany & Co. This yellow monster was on display at Tiffany on 5th Avenue for 70 years where it has had millions of admirers. At the time of cutting, Charles Tiffany was unsure of the rarity of the piece as South Africa was producing a healthy measure of yellow stones. But, in the following years, the depth of colour possessed by the emblem stone was confirmed as exceedingly rare and valuable.

So what causes a diamond to be yellow? Here comes the science…

Diamonds are made up of mainly carbon and when one has absolutely no other elements within its structure it possesses no colour and would be graded as a D.

All other diamonds contain other chemical elements, most often nitrogen. Since the nitrogen atoms do not have the same number of electrons as the carbon atoms, they bond with the carbon atoms in such a way that one nitrogen electron remains free. The free electrons are able to partially absorb light, most often the blue and violet wavelengths. The diamond’s yellow colour results from the light that has not been absorbed. The different ways in which the nitrogen atoms are present accounts for the different intensity of yellow within the diamond.

The deeper colours are rarer and thus command high prices.

How are yellow diamonds graded? I am sure you have all heard of white diamonds being referred to as a G VS1 for example. The G stands for the colour. The internationally recognized GIA colour grading scale begins with the letter D (pure white) and ends at letter Z (tinted colour). It is beyond the Z grade that the stone would be referred to as a Fancy Coloured Diamond as opposed to a White Diamond. The lower down you go in the alphabet (so the more yellow you go) the less rare and less expensive the stone is. However after colour Z this is reversed!  The colour range for Fancy Coloured Diamonds includes four colour grades: Fancy Light Yellow, Fancy Yellow, Fancy Intense Yellow, and Fancy Vivid Yellow. The colour known commercially as canary or canary yellow actually refers to the GIA grade of Fancy Vivid Yellow.

Why are most yellow diamonds radiant or cushion cut?

The intensity of the stones can be clearly improved by choosing the most appropriate shape; as a result, the stone’s value will increase accordingly. The Radiant Cut and the Cushion Cut both respond beautifully to large yellow diamonds. The reason for this is that they ‘hold’ the colour well. Experience has shown that a Radiant Cut yellow diamond might be certified as “Fancy Yellow”, whereas the same stone would most probably be certified as only “Fancy Light Yellow” were it to have a round brilliant shape.

The Celebrities. There have been several celebrity yellow diamonds besides the aforementioned Tiffany stone.

The Eureka (Greek for “I‟ve found it!”) is the first recorded diamond to be found in Africa. The pale yellow diamond was found in 1866 by children playing along the Orange River in Hopetown, South Africa. Later, in 1867, the rough 21 carat diamond was officially recorded as the first authenticated diamond discovered in the history of Africa. The diamond was subsequently cut to its current 10.70 ct size and in 1967, a century after its discovery, De Beers bought the diamond and returned it to the African people. The South African government put The Eureka on display at the Kimberley Mine Museum where today it continues to bear witness to the beginnings of the country’s diamond industry.

The Incomparable is the largest faceted yellow diamond in the world. It is flawless and weighs 407.48 ct. It was found in the Democratic Republic of the Congo, supposedly by a little girl who was playing on a garbage heap next to a diamond mine. Its colour has been determined by the GIA as Fancy Brown Yellow.

The Kahn Canary is a flawless, rough diamond weighing 4.23 ct. Discovered in 1977 in the state of Arkansas, nick-named “The Natural State”,  this diamond has become the state’s unofficial symbol for its natural uncut triangular form. Former First-Lady Hillary Clinton was allowed to wear the diamond on several ceremonial occasions, including the inauguration of Bill Clinton as the President of the United States of America.

Thanks to Kulsen and Hennig, the coloured diamond specialists.

Pure Gold Genius

  • 26th January 2011 was the date.
  • The Birmingham School of Jewellery was the venue.
  • The speakers were the goldsmithing deity Martyn Pugh and laser welding guru Dr Anne-Marie Carey.
  • The title of the talk was ‘I want one of those in 24ct’.

I can’t remember the last time I went to a lecture and came out of there so inspired and in awe! The genesis of this lecture and it’s title occurred a decade or so ago when one of Martyn Pugh’s customers, on seeing one of his exquisite silver and crystal jugs said, ‘I want one of those in 24ct’.  24ct gold has a beautiful rich colour but is inherently soft. This softness makes it unsuitable for jewellery or tableware but this was all part of the challenge for Pugh. If you haven’t heard of Pugh, you should have! He is prolific British creator of tableware and jewellery and is the winner of several awards and his work is used in 10 Downing Street!

So how do you make 24ct gold tough enough to create a jug with and then pour claret out of? This was the question which Pugh had bouncing around in his head and what followed were groundbreaking in both the end result and processes developed. There is no need to go into too much technical detail here (mainly because it I don’t fully understand it!) but what Martyn had to do was research what micro alloys of gold were available and suitable. A micro alloy is where a tiny amount of another metal is joined with the gold. After many conversations with world leaders in the field of metallurgy and workshop trials involving leading craftspeople, a gold-titanium alloy was chosen. This was 23.9ct pure gold and 0.1ct titanium. On hearing this I first thought that this small amount of titanium could not affect the strength of the gold  – but it does – significantly. This alloy has been used over the past few decades to create jewellery but has not made a huge impact in the industry. Creating the sheets and components of the gold alloy to be worked on was no mean feat and bullion and casting experts were drafted in to figure it all out. Actually the whole project was a successful experiment in pooling the resources and expertise of the best metallurgic/casting/spinning/lasering/goldsmithing minds in the world!

One of the issues that came up when creating the pieces was invisibly joining the sections together – the jug was made up of about half a dozen or so pieces. This is where Dr Anne-Marie Carey came in – the laser wielding welding expert! Countless hours were spent in creating the perfect join which the pieces required. There was no previous research available in the welding of this alloy so Dr Carey had to develop her own. A challenge but highly rewarding.

Believe it or not, one of the most important applications in creating the tableware was good old Brasso! The alloy did not respond well to normal gold polishing methods so Martyn decided to give Brasso a shot and it worked perfectly  – as the image shows!

To those of you who work in metal you may appreciate what Pugh and Carey have achieved here. To sum it up – they have created the first pure (almost!) gold jug and developed the working of a lesser used alloy on a scale never before achieved. Praise be to Oppi Untracht for those who decide to commission the impossible.

In 2008 I returned from a trip to India inspired to use rich gold with platinum in my designs. I heard rumours of these elusive alloys which were hard enough for jewellery but they just remained as rumours. That is until last year when I had the pleasure of chatting with Martyn. It is my desire this year to create some jewellery using this beautiful alloy.  The only thing is that it is bloody hard to produce or source. But, like the Pugh, I will rise to the challenge!

World Gold Council’s six key trends for 2011

Dimiani Rose and White Gold Wedding Rings

The World Gold Council (WGC) has announced six key gold trends for 2011, as seen at Vicenza Fair in Italy last month.

The six trends focus on styles which were popular across gold jewellery at Vicenza, including a focus on gold as a ‘jewel’, delicate gold accents and popular shapes and themes.

Gold – the New Jewel
Gold prices have seen gold accents become a popular way to add a luxurious edge to jewellery designs, with gold becoming a ‘jewel’ to elevate a design. The incorporation of gold into wood or ceramic designs is both eye-catching and modern. Gold chains were nestled amongst silver in designs by SuperOro.

Precious & Delicate
The preciousness of gold was exemplified at Vicenza in delicate and detailed jewellery. High carat, slim chains were shown, combining elegance with classic style. Nanis’ Petites collection presented tiny gold charms on necklaces and rings. Gold detailing had been designed to imitate gemstones, using diamond-cut techniques to catch the light and the eye.

Openwork& Weaving
Expert craftsmanship on show at Vicenza showed how gold electroforming has been taken to a new level. Designers including Tre Spighe and Graziella showed bracelets, necklaces, earrings and rings that demonstrated a level of detail in gold jewellery which previously was only possible to achieve through hand-carving. Delicate, spidery, skeletal structures weaved through designs – pieces that expressed the beauty of the gold in the most intricate designs.

Texture & Colour
Hammered, diamond-cut and silk finishes were popular textures, creating much interest. A mix of textures were often combined in one piece to create eye-catching effects. Yellow, white and rose gold were combined by designers including Damiani.

Shapes of the Season
Gold hearts, pebbles, stars, seashells and flowers peppered pieces by Il Giglio, Sade and others. Gold Expressions’ Opulent Organics theme was seen throughout the industry at Vicenza Fair. Smaller details were complemented with bolder shapes alongside organic, free-form designs including corals.

Personal Expression
Expert gold craftsmanship found was shown through a trend for versatile jewellery, such as reversible designs; pieces that work with or without charms or those designed to lengthen or shorten chains. Customisable gold by designers including Neri Romualdo, Chimento and Mattioli offered versatility, modernity and the power of personal expression, something seen last year in the popular bead charm trend.

via  ProfessionalJeweller.com.

Brilliantly detailed trend report by Professional Jeweller – as always they are really helping to support and inform the industry. Trends have never been a huge influence with our work as we concentrate on creating more Timeless than Fashionable. Especially when it comes to our unusual engagement rings.  Saying that, it is good to know that we are on trend with Expert Gold Craftmanship which is something we have shouted about for a long while. The combination of white, yellow and rose gold by Damiani sounds delicious – we have seen an excellent response to Rose gold of late championed by our Celestial Rose Cocktail Ring.

Photo Shoot for the Satellite Cocktail Ring

The studio is booked at Powerhouse Photo – and these guys know how to take a pic! The subjects are two Satellite Cocktail rings! These are our most adventurous cocktail rings to date and we have one with Tourmilated Quartz and another with Fire Opal. I guarantee that these shots will knock you socks off so be prepared….

Image care of www.psychedelicporcupine.co.uk

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