Gemologists Uncover the Secrets Behind the Rarity of Red Diamonds

Red diamonds remain one of nature’s most elusive and captivating treasures. With only 24 specimens over one carat ever publicly recorded, their scarcity is legendary. Among them, the remarkable Winston Red has now taken centre stage at the Smithsonian National Museum of Natural History in Washington, DC.

This exceptional gem was donated in December 2023 by Ronald Winston, son of the renowned American jeweller Harry Winston. Weighing over one carat, the Winston Red is not only a visual marvel but also a scientific mystery—until now.

Recent research published in Gems & Gemology has provided unprecedented insight into what makes red diamonds so rare. Using advanced imaging and spectroscopic techniques, gemologists have identified that the Winston Red’s vivid crimson hue results from a combination of factors: a unique distribution of nitrogen impurities and a heavily deformed crystal lattice structure composed of tightly stacked red-to-pink layers.

These structural distortions—formed under extraordinary heat and pressure—are thought to alter the way light interacts with the diamond, giving rise to its intense red colour. Such conditions are extremely rare in the Earth’s mantle, further explaining the diamond’s scarcity.

Historical records trace the Winston Red as far back as 1938, when Jacques Cartier sold the stone to the Maharajah of Nawanagar. Combined with its cutting style and geological characteristics, the evidence suggests the gem likely originated from diamond-producing regions in Brazil or Venezuela.

For gemologists and collectors alike, the Winston Red represents both a scientific breakthrough and a pinnacle of natural beauty—an enduring reminder of the Earth’s ability to create something truly extraordinary.

Source: DCLA

One of the World’s Rarest Red Diamonds Goes on Display

The Winston Red, an extraordinary and exceptionally rare diamond, is now on show to the public — making it the only known pure red diamond of its kind currently on display anywhere in the world.

Weighing 2.33 carats, it holds the distinction of being the fifth-largest pure red diamond known to exist. To put that into perspective, fewer than two dozen red diamonds over one carat have ever been recorded, making this a truly exceptional stone.

It’s now on exhibit at the Smithsonian National Museum of Natural History in Washington, D.C., as part of a special showcase of natural coloured diamonds.

A team from the Gemological Institute of America (GIA), working alongside experts from the Smithsonian’s Department of Mineral Sciences and the Paris School of Mines, have conducted an in-depth examination of the gem.

GIA’s president and CEO, Susan Jacques, called the Winston Red “one of the most exquisite gems on Earth,” noting its intense deep-red colour and fascinating history. Red diamonds are incredibly rare, and among the more than one million coloured diamonds studied by GIA, a mere 0.07% were red — and just over half of those qualified for the elite ‘Fancy red’ grade awarded to the Winston Red.

Through advanced research, GIA scientists have identified the diamond’s colour origin and believe it likely came from either Brazil or Venezuela.

Tom Moses, GIA’s executive VP and head of research, shared his personal connection to the stone, having first examined it back in 1987. He recalled its striking deep red hue and historical significance — a diamond once sold by Jacques Cartier in 1938 to the Maharaja of Nawanagar.

The Winston Red is now the star attraction in a new exhibition at the Smithsonian, which features 40 other rare coloured diamonds from the Winston Fancy Color Diamond Collection. The collection was donated by Ronald Winston, son of legendary jeweller Harry Winston.

This exhibition is a rare opportunity to witness one of nature’s most elusive and captivating treasures — a true celebration of colour, history, and craftsmanship.

Source: DCLA

Smithsonian Acquires One of the World’s Largest “Fancy Red” Diamonds

Winston Red Diamond Will Be Unveiled to the Public at the National Museum of Natural History Alongside a Rainbow of Colorful Diamonds

The Smithsonian’s National Museum of Natural History will unveil the Winston Red Diamond and Winston Fancy Color Diamond Collection Tuesday, April 1—an extraordinary showcase of some of the world’s rarest and most dazzling gems.

The breathtaking diamonds were gifted to the museum by Ronald Winston, the son of distinguished jeweler and gem collector Harry Winston. In 1958, Harry Winston donated the iconic Hope Diamond to the Smithsonian, laying the foundation for the National Gem Collection. Now, the Winston Red Diamond and Winston Fancy Color Diamond Collection will be featured in the museum’s Winston Gallery, offering visitors the rare opportunity to witness one of the finest collections of fancy color diamonds ever amassed.

“This ranks among the most significant gifts ever received by the Smithsonian,” said Kirk Johnson, the Sant Director of the National Museum of Natural History. “The Winston diamonds are unprecedented in their beauty and rarity, and we are thrilled to welcome them as additions to our National Gem Collection. We extend our gratitude to Ronald Winston for making this gift to the nation possible.”

Natural red diamonds are among the rarest gemstones on Earth, and the Winston Red Diamond stands out as exceptional. At 2.33 carats, it ranks among the largest diamonds ever bestowed with the coveted “Fancy red” color grade by the Gemological Institute of America (GIA). Researchers estimate that less than one in 25 million diamonds is a Fancy red, and the Winston Red Diamond is one of the most exquisite in existence.

“The red diamond is the highlight of my career, and I have never seen anything else like it,” Ronald Winston said. “This donation to the museum represents my life’s achievements in this domain, and I am so happy to share this collection with the Institution and the museum’s visitors.”

While some colorful diamonds get their pigmented appearance from atomic impurities in their crystal structure, the Winston Red Diamond’s striking crimson hue is the product of extremely high pressure and temperature conditions deep within the Earth that strained and altered the crystal. The diamond features an old mine brilliant cut, a style that predates the round brilliant cut used in engagement rings today. With fewer, larger facets, this distinctive cut suggests the stone was fashioned before the mid-1900s. A study on the science and history of the Winston Red Diamond is forthcoming in the spring 2025 issue of Gems & Gemology, the quarterly professional journal of the GIA.

“In this collection, we have diamonds in colors I could never have dreamed of,” said mineralogist Gabriela Farfan, the Coralyn W. Whitney Curator of Gems and Minerals. “These gems give us the opportunity to share with our visitors the full range of colors in which diamonds occur.”

The Winston Red Diamond will be displayed alongside 40 other gems from the Winston Fancy Color Diamond Collection. The diamonds will be arranged in a radiant rainbow of color, featuring every shade imaginable from deep teal to soft peach.

The Winston Red Diamond and Fancy Color Diamond Collection are the result of 60 years of dedicated acquisitions by Ronald Winston. Alongside the Hope Diamond, the new display will honor the legacy of the Winston family and showcase the brilliance and rarity of these exceptional gems.

Source: DCLA

Rare Orange-Red Diamond Appears at Auction

 Rare Orange-Red Diamond Appears at Auction

                    1.21-carat, fancy-orangey-red

Heritage Auctions has unveiled a 1.21-carat, fancy-orangey-red diamond that will go under the hammer at its Fall Fine Jewelry Signature auction on September 29.

“This gem is one of only a few diamonds to display enough saturation and intensity to be graded as a true red,” said Jill Burgum, Heritage Auctions’ executive director of fine jewelry. “Adding to the allure, the cause of a red diamond’s color remains a mystery to scientists, making this stone even more of a marvel.”

The stone has a presale estimate of $100,000 to $150,000.

Other notable diamonds included in the sale are a 17.63-carat, fancy-intense-yellow diamond ring from the estate of Dallas philanthropist Mary Anne Sammons Cree, which is expected to fetch $300,000 to $400,000. More than 125 jewels from Cree’s collection are up for sale, with the proceeds going to the Communities Foundation of Texas as well as Dallas-area nonprofits.

Source: DCLA

Classic car prices drop but diamonds and wine shine

Old Master paintings and classic cars have lost the luster, But the uber rich have seen their jewellery, fine wine and musical instruments jump in value again.

This according to to the Blue blooded UK bank Coutts’ passion index of the finest things. Now in its twelfth year.

Read more : DCLA

Rough Market Cools Despite $572M De Beers Sight

 

De Beers Orapa mine

The rough-diamond market slowed during last week’s De Beers July sight, with prices on the secondary market decreasing.
De Beers sold $572 million of rough in the sixth sales cycle, an increase of 6% from the previous sight and 8% from the same period a year ago, the company said Tuesday. However, rough dealers were reselling boxes of De Beers goods for no premium, or at a loss, in contrast to the buoyant activity in the first half of the year, sightholders said.
While De Beers kept its prices generally steady, prices on the secondary market were about 4% to 5% lower than they were following the June sight, dealers reported. “Taking into account the real cost of the boxes [including tax, broker fees and other costs], the box prices represented a loss to the sellers,” Dudu Harari of diamond broker Bluedax said in a report on the sight.
The cooling of the market comes as diamond cutters are finally realizing that the mismatch between rough and polished prices has made it difficult for them to make money on goods, one rough broker told Rapaport News on Tuesday.
Demand for polished diamonds remains weak, resulting in slim profit margins for manufacturers, sightholders said, as rough prices increased an estimated 3% in the first half. “This sight, we saw a paradigm shift,” the rough broker explained.
“There wasn’t much demand for De Beers boxes on the secondary market. This was a very significant difference from sight five. “The wheels have come off the bus as far as the rough market is concerned,” the broker added. “If something doesn’t change at the end of the pipeline, we could see a drop in rough prices.” De Beers, meanwhile, said demand for its goods was solid across its product range, as the miner had reported in previous sights.
“With Diwali being earlier than normal in 2017, we saw some demand from Indian diamantaires pulled forward from sight seven,” said De Beers CEO Bruce Cleaver. “This was due to these customers needing to make rough-diamond purchases in sufficient time to complete their polishing before the holiday begins.” De Beers continued its recent practice of not offering any “ex-plan” goods — excess rough that the miner makes available beyond what it has agreed to supply sightholders — according to the anonymous broker.
Buyers reported shortages in certain rough categories, in line with earlier sales this year.

 Source:diamonds.net

Sarine Claims Superior Accuracy for Grading Tools

Sarine Technologies’ new automated color- and clarity-grading systems are yielding more reliable results than manual graders, the company has claimed.

Sarine Clarity, which uses technology to analyze flaws in polished diamonds, showed a 97% correlation with the grades given by a reference group of human gemologists, while Sarine Color matched them 99% of the time, Sarine said Sunday.

Read more: DCLA 

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Rio Tinto Debuts Biggest Red Diamond in Tender History

 

The 2.11 carat radiant cut fancy red Argyle Everglow, the top lot of the 2017 Argyle Pink Diamonds Tender New York.

Four graded fancy red and another four as purplish red. There were also two violet diamonds and one blue, with the remaining 41 graded pink.

Following the preview held this week in New York, the diamonds will travel to Hong Kong and then come back to New York in September, before returning to Australia where they were mined.