Diamonds are forever...

Diamonds are forever...

The epic journey led him from Paris to Persia and, finally, to the fortified city of Golconda, the seat of power of a fabled kingdom in south-central India, in what today is the state of Hyderabad.

Known to Europeans since the days of Marco Polo, Golconda was a trading centre for diamonds from the Kollur Mine, the most prestigious among a group of local mines that produced, from ancient times through the end of the 19th century, history’s best-known diamonds, including the Hope, the Koh-i-Noor and the Regent.

On this journey, Tavernier was permitted to examine the Great Mogul Diamond, a colossal gem shaped like half of a hen’s egg and named after Shah Akbar, the third of India’s Mogul emperors.

The stone vanished soon after, though unconfirmed sightings of it, or smaller gems cut from it, have been reported over the centuries.

In Travels in India, the merchant’s 1676 memoir, he described the diamond as “a round rose in shape, very high at one side.”

“Its water is beautiful and it weighs 3191/2 ratis, which are equal to 280 of our carats, the rati being seven-eighths of our carat,” Tavernier wrote.

The reference to the stone’s “water” is lost upon most modern jewellery enthusiasts. But to the earliest gem traders, that elusive quality meant everything.

Until the advent of more sophisticated cutting techniques in the late 17th century, brilliance, or the quality of light return that allows a stone to sparkle, had little bearing on a diamond’s value. Instead, gems were prized for the purity of their crystal. The most transparent, and coveted, diamonds were known as “gems of the first water.”

François Curiel, Christie’s chief jewellery specialist, said a Golconda diamond has a quality “like water or a river going through the gem.”

Richard Wise, a gem dealer in Lenox, Massachusetts, said, “You hear them called ‘whiter than white’.” Wise is the author of The French Blue, a fictional account of Tavernier’s discovery of the 116-carat blue diamond that would eventually give rise to the 45.52-carat Hope.

Connoisseurs have rediscovered the allure of these legendary gems. “In the last five years, the market for Golcondas has mushroomed,” said Rolf von Bueren, chairman of Lotus Arts de Vivre, a jewellery manufacturer in Bangkok that obtains them from a trusted supplier in New Delhi. “Like so many things in the world, what wasn’t rare 20 years ago is rare today. It’s like peeling an onion: You take off one layer and that becomes common and known, so you peel off the next layer. In diamonds, nothing surpasses Golcondas.”

What distinguishes Golcondas and their ilk from the vast majority of diamonds is their Type IIa designation, referring to gems that are devoid of nitrogen. The element, present in Type I diamonds, lends stones a slightly yellowish tinge.

“Only 2 per cent of all diamonds are found in this Type II category,” said Thomas M Moses, senior vice president of laboratory and research at the Gemological Institute of America, GIA. “Because they’re so pure, they transmit UV and visible light that Type I diamonds block. They have a clear, limpid, transparent nature. They look like ice cubes.”
Which is not to suggest that Type II diamonds are always colourless. Occasionally, they are brown or pink, and still rarer are those infused with a delicate blush of blue or gray. Categorised as Type IIb, the blue gems, also nitrogen-free, owe their hue to traces of boron.

The Golconda mines have closed. But other sources of Type II diamonds are still in production. “Today, the exact same stones come from Lesotho and South Africa,” said Marvin Samuels, chief executive of Premier Gem Corp., a New York diamond supplier specialising in large, fine stones.

Indeed, modern dealers of such diamonds — like David Klein, executive director of Leviev, and Laurence Graff, the London merchant who is regarded by many as a latter-day Tavernier — often use the terms Golconda and Type IIa interchangeably.

The buzz about these rare gems has been growing. Last month, for example, Chopard took the unusual step of publicising its acquisition of an 85-carat emerald-cut Type IIa diamond “of extreme purity matched by sparkling whiteness.”

“It’s the sexiest emerald-cut I have ever seen,” said Caroline Gruosi-Scheufele, co-president and creative director of the Swiss luxury jeweller. “I don’t want to let it go unless I know it’s going to good hands — to someone who appreciates the beauty and not just the money.”

Gruosi-Scheufele declined to discuss its value, but auction estimates for stones of comparable quality are in the millions of dollars.

A 56.15-carat heart-shaped Type IIa diamond is the headline gem in Christie’s May 18 jewel sale in Geneva. The stone is of D colour — based on GIA’s colour scale for diamonds, which ranges from D for the most colourless to Z, for diamonds with a distinct yellowish tint — and is estimated to be worth $9 million to $12 million.

A smaller, coloured, Type IIa diamond, a 10.09-carat Fancy Vivid purplish-pink cushion cut, is expected to fetch $12 million to $15 million at Christie’s April 12 jewel sale in New York.

Even producers of synthetic and treated diamonds are hoping to cash in on the buzz. On March 1, GIA reported that its laboratory had identified an “impressive” 38.59-carat F colour cushion cut , treated by a high-pressure, high-temperature process, that “corresponded to a typical Type IIa diamond.”

Moses said he was confident that artificial and treated stones could be distinguished from natural ones. Still, the quest to produce synthetic diamonds of this size and quality underscores the extreme desirability of the genuine article. For true connoisseurs, these are stones that stay in the memory for decades.

As Harry Winston’s chief gem buyer in 1992, Walter McTeigue, co-founder of the high-end jeweller McTeigue & McClelland, bought a 16-carat marquise-shaped diamond from two Argentine brothers whose mother had purchased the stone from the firm in the 1960s.
“They called it a D colour, but when I compared it to other D stones, it made them look like H colours,”  McTeigue said. “I described it as a C. I’m sure it was a Golconda because of that.”

“We sold it to Japan for $700,000,” he said. “It was the biggest sale Harry Winston had all year.” He added: “These days, it could be that much per carat.”