Graff celebrates yellow diamonds

In celebration of Haute Couture Week, Graff is exhibiting a collection of yellow diamonds at its flagship Paris boutique to complement the unveiling of its new high jewellery necklace

Launched yesterday (4 July 2023), visitors to Sunrise: A Celebration of Graff Yellow Diamonds will discover a world of rarity and lustre through a stunning showcase of high jewellery pieces featuring rare yellow diamonds, accompanied by displays detailing Graff’s storied history with these incomparable stones.

The House’s latest high jewellery creation features an extremely rare 30ct fancy intense yellow pear shape diamond, accompanied by a further 138ct of yellow and white diamonds.

Every element of the piece has been created using the stone-led design techniques for which the Graff atelier is renowned and has been crafted to emphasise the elegant silhouette of the centre stone.

Graff design director, Anne-Eva Geffroy explained: “Before we design, we study each diamond carefully to uncover the secrets that lie within its depths.

“Only then do we design, and when we do, we work to accentuate the natural beauty of each stone.

“The fancy intense yellow diamond set into this piece gives a golden sunshine glow.

“Yellow diamonds bring so much joy.

“It is an honour to be inspired by stones that radiate such beauty.

“The yellow diamonds we work with are exceptional in quality, cut, and quantity.

“Very few jewellers have the luxury of such a wide range of colour.”

In vibrant halos of yellow and white diamonds, stones radiate outwards from the central fancy intense yellow diamond to replicate the rays of the sun.

A perfect synthesis of diamond design and hand-craftsmanship, each bespoke setting has been meticulously assembled by master artisans within the House’s London workshop.

CEO of Graff, Francois Graff added: “Celebrating Graff’s legacy of innovation and leadership in presenting the highest quality rare diamonds, this will be the most significant collection of yellow diamonds that have ever been brought together in one place, including a fancy intense yellow stone of incomparable beauty.

“These are truly jewels that represent the very best of Graff.”

Further pieces on display in the showcase at the flagship Paris boutique include unique high jewellery necklaces, Tribal-inspired jewels, earrings, and single-stone rings that unmistakably express Graff’s design DNA through the combination of superb stones with bold designs and unparalleled craftsmanship.

An impressive roster of important and famous yellow diamonds have passed through the House over the course of its history, beginning with the Star of Bombay in 1974.

The Star of Bombay is an historical yellow stone that was re-cut and polished by Graff using revolutionary expertise and new techniques.

Since then, Graff has introduced many famous and historical yellow diamonds over the years, including the 118.08ct Delaire Sunrise and the 132.55ct honey-hued Golden Empress.

Sunrise: A Celebration of Graff Yellow Diamonds is currently exhibiting at Graff Rue Saint-Honoré throughout Haute Couture Week in Paris.

Source: professionaljeweller

Antwerp Diamond Polishers Develop Device That Uses AI to Grade Colored Stones

Fancy colour diamonds
Fancy colour diamonds

Chroma Diamonds founded by Alexander Appels and Jan De Henau is a relatively new company in the Antwerp diamond district, which specializes in colored diamonds. Stymied by the relatively “subjective process of color grading”, the 2 have set out on a mission to develop a device that provides more objective measurements for the grading of colored stones.

The device will utilize AI gathering data points and becoming smarter with each new set of inputs. They believe with sufficient time the device would learn enough to be able to more accurately grade certain stones, especially in resolving cases where certain grading criteria place the value of diamond on the edge of a color category but not quite enough to satisfy it being classified in the next grade above.

“Customers come to us with high expectations. After all, the value of their diamond is determined by, among other things, the color and intensity of that color, and let it (partly) depend on the cut and the people in the grading office, we hear. Because it is they who assign the diamond an official color, and therefore also determine its value definitively,” explains Appels.

Though this idea is not new to the Diamond District the duo has taken things one step further receiving support from the innovation process of the City of Antwerp. They plan on using and testing the device in their own business first as proof-of-concept before taking it to the greater market.

Source: Bloovi

303ct. Polished Yellow to Hit Auction Block at Sotheby’s

303.10-carat Golden Canary diamond
303.10-carat Golden Canary diamond

Sotheby’s will offer a yellow diamond weighing more than 300 carats at its upcoming New York auction, where it is expected to bring in more than $15 million.

The pear-shaped, 303.10-carat, fancy-deep-brownish-yellow stone is one of the largest polished diamonds in the world. It is also the largest flawless or internally flawless diamond ever graded by the Gemological Institute of America (GIA), Sotheby’s said Monday.

Initially called the Incomparable Diamond, the stone was recut from its original 407-carat shield shape to deepen the color and brighten the hue, and renamed the Golden Canary. As the highlight of the December 7 Magnificent Jewels sale, it will be offered without reserve, with bidding starting at $1, Sotheby’s noted.

The Golden Canary was first discovered in the early 1980s in a pile of rubble by a young girl playing in the backyard of her uncle’s house, Sotheby’s noted. Miners from the nearby Miba diamond deposit had considered the stone to be too bulky to be diamond bearing and had discarded it. The girl gave the 890-carat rough to her uncle, who sold it to local diamond dealers. The diamond has since been displayed in multiple museums.

“The demand and appetite for [extraordinary colored diamonds] continues to grow,” said Quig Bruning, head of jewelry for Sotheby’s Americas. “Steeped in history, the Golden Canary is one of the most exquisite diamonds to ever be discovered, not only for its sheer size and intensity in color, but for its stunning beauty that is sure to captivate collectors around the world.”

Sotheby’s will showcase the diamond on a world tour prior to the auction, with stops in cities including Dubai; Taipei, Taiwan; Geneva; and Hong Kong.


Crater of Diamonds visitor finds 4.38 carat yellow diamond

4.38 carat rough yellow diamond

A California woman visiting the Crater of Diamonds State Park in Arkansas found a 4.38 carat yellow diamond after less than an hour of searching.

Arkansas State Parks said Noreen Wredberg of Granite Bay was visiting the park with her husband on Thursday and had been looking for gems in an open field for about 40 minutes when she spotted something shiny on the surface.

“I didn’t know it was a diamond then, but it was clean and shiny, so I picked it up,” Wredberg recalled.

Wredberg’s husband, Michael, took her find to the Diamond Discovery Center, where it was identified as a 4.38 carat yellow diamond.

“When I first saw this diamond under the microscope, I thought, ‘Wow, what a beautiful shape and color,'” Park Superintendent Caleb Howell said. “Mrs. Wredberg’s diamond weighs more than four carats and is about the size of a jellybean, with a pear shape and a lemonade yellow color.”

Officials said Wredberg’s discovery is the largest diamond found at the park since October 2020.

Wredberg said she hasn’t yet decided whether to have the diamond cut or to leave it as is.

“I don’t even know what it’s worth yet. It’s all new to me,” she said.


The Largest Diamond Ever Mined in North America up for Auction

204.36-carat “Dancing Sun” fancy intense yellow diamond

A 204.36 carat fancy yellow diamond hits the block at the Christie’s Magnificent Jewels auction on June 8 in New York City. The Dancing Sun, with an estimate of $3.5 million to $5.5 million, is the largest polished diamond ever mined in North America.

It was cut from a piece of rough weighing 552.74 carats. Six smaller diamonds were cut from the same rough, ranging from 14.52 to 1.06 carats, and are also included in the sale. All six are set into rings. The rough diamond came from the Diavik Diamond Mine, the second to open following the great Canadian diamond rush of the 1990s.

The previous record for the largest known gem quality rough ever mined in North America was the 187.66 carat Foxfire rough, also mined at Diavik. It was cut into several gems, including a pair of pear shapes weighing 37.87 and 36.80 carats, auctioned at Christie’s New York in December 2018 for $1.5 million.

73ct. Yellow to Shine at Sotheby’s New York Sale

73.11 carat yellow diamond

Sotheby’s will offer a fancy-vivid-yellow diamond ring at its New York sale next month, estimating the piece could fetch up to $3 million.

The cut-cornered square step-cut, 73.11-carat, VS2-clarity jewel by Mayfair designer Glenn Spiro, called The Sienna Star, is one of the largest fancy-vivid-yellow diamonds to come to auction, Sotheby’s said Wednesday. The piece is one of the top items at the June 9 Magnificent Jewels sale. The auction will feature jewelry for the “Roaring Twenties 2.0” as people return to the social scene following long lockdowns, Sotheby’s noted.

A private collection of six jewels with a combined estimate of more than $13 million are another headline lot at the New York sale. Those include a necklace by Andrew Clunn, set with 28 oval-shaped diamonds totaling over 168 carats, which carries a high estimate of $3 million, and an emerald-cut, 23.59-carat, D-color, internally flawless, type IIa diamond ring with an upper valuation of $2.8 million.

A Colombian emerald and diamond garland necklace by Harry Winston, estimated at up to $2.5 million, and a 13.02-carat Burmese ruby ring, mounted by Carvin French, with a $2 million high valuation, are also part of the collection. Proceeds from the sale of those six items will be donated to charity.

Additionally, Sotheby’s will showcase a Bulgari ring with a 25.29-carat Kashmir sapphire flanked by diamonds, which it expects will bring in up to $3 million. Meanwhile, a modified square brilliant-cut, 3.75-carat, fancy-intense-pink, VVS1-clarity diamond ring, accented by triangle-shaped and round diamonds, is estimated to fetch up to $2.5 million.

The auction house will present jewels from the collection of philanthropist Margaret Jonsson Rogers, the daughter of Texas Instruments founder and Dallas mayor J. Erik Jonsson, as well as property from the estate of Mary Ethel Weinmann, the daughter of Count and Countess André de Limur, it added.


24ct. Yellow Diamond Beats Estimate at Christie’s

Christies Yellow Diamond

A 23.58-carat diamond ring was the top lot at Christie’s Jewels Online sale, fetching well above its high estimate.

The piece, which featured a cut-cornered rectangular modified brilliant-cut, fancy-yellow, SI1-clarity stone, bracketed by two triangular-cut diamonds, brought in $325,000 against its $300,000 upper estimate, Christie’s said Wednesday. In total, the auction running from January 27 to February 10 garnered $2.7 million, with 98% of the items on offer finding buyers.

Two diamond rings sold for $81,250 each, just above their high valuations. One contained a round, 4.18-carat, F-color, VS2-clarity diamond. The other was set with an emerald-cut, 3.56-carat, D-color, internally flawless, type IIa diamond, flanked by two smaller emerald-cut and two triangular-cut diamonds. A diamond medallion necklace by Graff, bearing a total weight of 35.38 carats, also realized $81,250, within estimates.

A number of Graff diamond and gemstone jewels were sold without reserve at the auction. Those included a pair of emerald and diamond earrings, which brought in $40,000, beating estimates, and a ruby and diamond ring, which smashed its high valuation, fetching $32,500.

Meanwhile, a pair of aluminum Violet earrings by designer JAR garnered $13,750, more than four times their upper estimate.


6.70 ct Zimmi Yellow Diamond could Fetch $700,000

Zimmi Yellow Diamond

A rare 6.70-carat VS1 natural fancy deep yellow diamond from the famous Zimmi mine, in Sierra Leone, could fetch as much as $705,000 at auction.

Canary yellow diamonds from Zimmi can command double the price of other fancy yellows because of their uniquely high color saturation levels. Yellow Zimmi stones over five carats are extremely rare.

This gem will lead the Tiancheng International Jewellery and Jadeite Autumn Auction 2020 in Hong Kong on 28 November.

Also at the sale is a pair of Zimmi natural fancy deep yellow diamond earrings 3.03 carat and 3.01 carat with an estimate of up to $320,000.

The Zimmi mine is in the heart of the rainforest region of Sierra Leone where the Mano river marks the border with Liberia.

Yellow diamonds occur when a single nitrogen atom replaces a carbon atom, absorbing the violet and blue light.

Source: IDEX Online

Study yields new insight in hunt for rare, valuable yellow diamonds

Yellow diamonds, some with colourless cores

A new study by University of Alberta scientists could help guide the search for rare, high-value yellow diamonds in the Canadian North.

The researchers, led by PhD student Mei Yan Lai, examined the chemical makeup of stones recovered from the Chidliak and Ekati mines in Northern Canada to get a better understanding of how they formed.

“Without this research, we wouldn’t know that two separate formation events occurred, and that the second, more recent event is responsible for the yellow colour,” explained U of A diamond geologist Thomas Stachel.

“The more we know about the origin of these potentially high-value diamonds, the better results for diamond exploration and value creation in Northern Canada.”

Lai said they wanted to understand the origin of the yellow colour in the diamonds from the two deposits.

“Canadian yellow diamonds have never been studied spectroscopically in detail. Our results suggest that the cause is the preservation of unstable single nitrogen atoms preserved inside the diamonds,” explained Lai, who conducted this research as part of her master’s studies in the Diamond Exploration Research Training School under the supervision of Stachel.

The research team determined that some yellow diamonds contain colourless cores, meaning that the yellow outer layers crystallized on top of clearer centres. Lai determined that the yellow diamonds crystallized no more than 30,000 years before the kimberlite eruptions that brought them up to Earth’s surface.

“Our analysis shows that the colourless cores in these yellow diamonds are about one billion years older,” Lai said. “In fact, the carbon isotope compositions and nitrogen concentrations of the colourless cores and yellow outer layers are significantly different, suggesting that they formed in at least two distinct events and involved different diamond-forming fluids.”

The researchers said discovering a potential new source of yellow diamonds in the Canadian North is economically significant, as the previous main source of high-quality yellow diamonds, the Ellendale Mine in Western Australia, was recently shut down.

The discovery of colourless cores in some of the yellow diamonds may also be of interest to the jewelry trade, said Lai.

“Occasionally, rough yellow diamonds lose their vibrant yellow colour after being cut and polished—probably because this kind of diamond has a thin layer of yellow overgrowth on top of the geologically older colourless core,” she said.

The project is a collaboration with Dominion Diamond Mines and Peregrine Diamonds Ltd. Part of the analyses were done at the Gemological Institute of America.

The research is supported by a bursary through DERTS, funded by the Natural Sciences and Engineering Research Council of Canada’s Collaborative Research and Training Experience program.

The study, “Yellow Diamonds With Colourless Cores—Evidence for Episodic Diamond Growth Beneath Chidliak and the Ekati Mine, Canada,” was published in Mineralogy and Petrology.

Source: miragenews

Gem Diamonds Unearths 135ct. Yellow

135ct Yellow Diamond

Gem Diamonds has recovered a 135 carat yellow at its Letšeng mine in Lesotho, the third significant colored-diamond discovery at the deposit this year.

The company retrieved the high quality, type I stone on June 21, three months after the mine yielded a similar quality yellow diamond weighing 134 carats. Those discoveries follow a two year gap in the recovery of yellow diamonds weighing more than 100 carats from Letšeng. In June 2017, the miner found a 151.52 carat yellow.