"One year's Argyle production fills a small truck, but the pink diamonds would only half fill the ash tray."
- David Fardon in 1995 on the rarity of pinks. Today the ash tray is all but empty!
Pink and Red Diamonds
The Argyle mine in the far north of Western Australia has, for 3 decades, produced most of the world's very rare red and pink diamonds. Argyle has supplied almost all the worlds purple pink diamonds; other mines produce paler more orangey pink diamonds.
Initially a huge open cut mine, now nearing the end of its life, RioTinto has begun developing an underground mine. The open cut is so deep trucks drive down the spiral pit for a 10th of the mines peak production. Rio is $2 Billion over budget and the underground mine is still not operating. RioTinto is selling the mine as it does not fit their portfolio. All this has greatly reduced the availability of pink diamonds and the already high prices, 10 to 100 times those of equivalent colourless diamonds, is set to soar even higher as investors snap up decent stones.
Argyle offers its finest 50 or so pink diamonds each year in a sealed bid tender. In some years the tender includes a red and, occasionally, a grey blue
diamond. The event has become widely reported. The tender is not open to the public but if you are interested to invest in a pink diamond Holloway Diamonds will invite you to a viewing and bid on your behalf. Stones often fetch more than half a million dollars.
Champagne or brownish coloured diamonds are the most affordable coloured diamonds costing less than colourless white diamonds. The Argyle mine in the far north of Western Australia has, for 3 decades, produced most of the world's champagne diamonds.
Initially a huge open cut mine, now nearing the end of its life, Rio is $2 Billion over budget and years late on an underground mine greatly reducing the availability of champagne diamonds.
Prices for colour C1 (lighter) to C6 (the colour of cognac) are all similar. Lighter stones (C2 to C3) are popular because they sparkle more than darker stones. More intense colours are popular because they are more unusual. Supply and demand are balanced.
There are different secondary colours. Warmer colours are more attractive than grey-greenish browns (these do not come from Argyle). Intense golden and rusty colours are called Fancy Cognac*, or C7 and cost a little more because they are rare.
Pinkish tinged champagnes are sought after and expensive. Champagne diamonds (and most other coloured diamonds) are often more heavily included than white diamonds.
*The French cognac community do not allow the use of ‘cognac’ – but the champagne people love the association!
What Causes Colour in Diamond?
Diamonds are pure carbon that crystallised more than 100km beneath the earth's surface under immense heat and pressure and have been shot to the surface within an hour or two in a volcano. They are ‘snap frozen’ - if the journey takes too long they revert back to graphite or carbon gases. Sometimes other atoms are trapped in a diamond as it grows or during its violent ride to the surface. Nitrogen is the most common; the tiniest amount causes blue light to be absorbed giving the diamond a yellowish colour. Australia Argyle diamonds are an exception, they are very pure and the cause of the rare pink colour is a freak of nature. Unfortunately the cause of colour is stress that means most are heavily included.
Hope Diamond 45.53 Carats
Natural blue diamonds are a light greyish blue shade, a more "steely" colour than sapphire. The most famous blue diamond is The Hope diamond in Washington's Smithsonian Institute. This stone is steeped in legends of horrible deaths that befell many of its owners, from guillotining during the French Revolution, to a Wall Street broker jumping to his death in 1930. A lead molding from the ‘French Blue’ was scanned by Scott Sucher using my associates advanced technology to prove the stone was recut from the earlier versions. New York jeweller Harry Winston purchased it to donate to the Smithsonian and only owned it briefly. While his insurance company and armed couriers were discussing the cost and method of delivering the priceless gem to Washington, it’s reported that Harry strolled down to the post office and posted the diamond in a cigarette packet as ordinary mail!
Dresden Green 41Carats
Green diamonds have come in contact with radioactive minerals such as uranium. Radiation stains the outside of the diamond, so the cutter must be careful not to cut away too much of the green "skin". Authenticating that the radiation occurred naturally requires laboratory analysis. Often the cutter submits the stone as rough and during the cutting process so the lab can authenticate the rough stone.
Yellow and Orange Diamonds
To be called a Fancy colour means the diamond has more colour than Z (face up) on the GIA D-Z white diamond grading scale. Fancy yellow diamonds come in a range of hues from greenish yellow to orangy-amber. They start at similar prices to white diamonds and prices rise with increasing intensity. Connoisseurs in the trade use the term "canary" to describe intense yellow. Burnt orange Argyle champagne's are a less expensive alternative to very expensive pure gold or orange colours. The Ellendale mine, discovered about the same time as Argyle, has been opened and operating for the past several years and it has produced many fine fancy yellow diamonds
A little known and quite rare diamond is a white opalescent diamond. These are collector's oddities and we have a small selection at Holloway Diamonds. They are a lot less expensive than transparent colourless diamonds, and we think they were a real bargain. There have been articles written about them recently in Gems and Gemmology, a journal created by the GIA. Who knows, they may become the next fashion thing like black diamonds.
Pave' set Black diamonds are popular in high-fashion jewellery. We have a large collection of the latest black and white diamond designs. They are often used in men's jewellery. Most of the black diamond fashion jewellery is made with small irradiated treated coloured diamonds. Most large black diamonds are low clarity diamonds and when heated the inclusions go black. Natural untreated black diamonds have been heated in the earth and are indistinguishable from stones that have been heated by man. Good surface lustre of heat treated blacks is rare.
GE Bleached Pegasus Diamonds
Disclosure is an issue of great concern. The General Electric Company was equal first to make synthetic diamonds for industrial abrasives in 1955. In 1999 GE's R&D team0 discovered a way to improve the colour of some rare large diamonds (type II) using an advanced high pressure / high temperature treatment (HPHT). The whitened gems more than doubled in value marketed as Belataire™ diamonds. The gem industry requires gem dealers to disclose any treatments on invoices. But GE maintained the process duplicated nature and could never be detected, thus disclosure was unnecessary. Within months gemologists discovered tests to identify HPHT diamonds.
"Genetically Modified" Colours
Demand for coloured diamonds is outstripping supply; prices are going through the roof. Technology is used to create artificial colours using lower grade diamonds. Labs can make many beautiful colours in any size, shape or consistently matched quantity. The colours are created with sophisticated high temperature, high pressure and irradiation processes.