Rio Tinto has announced what will be its final Beyond Rare™ Tender—the third and last of its annual “Art Series.”

This closing chapter, titled Into the Light, brings together 92 amazing fancy color and colorless diamonds, in 52 Lots, totaling 45.44 carats from two of the company’s iconic sources: the Argyle Mine in Western Australia and the Diavik Mine in the Northwest Territories, Canada.

With Argyle having been officially closed since late 2020, and Diavik due to wind down next year, 2026, this tender is very much a tribute to the legacy of both mines. The collection includes six “Masterpieces,” carefully matched sets that highlight the best of each mine’s production, along with 39 single stones and seven additional curated sets.

These Diamonds Are Outstanding!

Rio Tinto’s Patrick Coppens, General Manager of Sales and Marketing, said: “It is hard to overstate the importance of this final collection from two extraordinarily beautiful places on earth - the East Kimberley region of Western Australia and the Northwest Territories of Canada."

“No other mining company in the world has custody of such an exquisite collection of diamond colours, shapes and sizes and we all pay tribute to the men and women who have worked so hard over many years to bring them to market.”

The final Argyle pink, red, and violet diamonds in the tender come from the mine’s legacy inventory. In other words, these are among the last examples of their kind that will ever come to market from Rio Tinto.

Tap here for lots of pictures and more details of the LAST Beyond Rare™ Tender!

Rago Arts’ September 10, 2025 auction in New Jersey offered more than just beautiful jewels—it offered a window into jewelry history. Art Nouveau, Art Deco, and antique pieces shared the stage, each demonstrating the aesthetics and materials that defined its moment in time.

Together they show how design moved from organic, nature-inspired forms to the sharp lines and symmetry of modernism.

Here, we’ve gathered a few highlights to give you a closer look at how these styles came to life.

Art Nouveau

Here is a classic Art Nouveau pendant depicting a woman with rose-cut diamond head piece and a plique-à-jour enamel iris, suspending a pearl, hung from a fine link chain; circa 1900s

Yellow gold

Sold with Didier Antiques box

Estimate: $1,500–2,000

Sold: $4,445

Tap here for more Art Nouveau and Art Deco jewels sold at Rago Arts!

Gary Roskin

Roskin Gem News Report

When we talk about akoya cultured pearls, we usually think of the traditional mollusks used for pearl farming — members of the Pinctada fucata species complex, with P. fucata (martensii) being the classic choice in Japan for over a century. As you probably know, these pearl oysters thrive in cooler waters, which slows nacre deposition and results in that unmistakable akoya look: perfectly round shape, mirror-like luster, and usually a thinner nacre layer compared to their South Seas cousins. Thin nacre is one of the trade-offs of akoya pearls, and durability has always been part of the conversation.



That is, until now!

GIA's Summer 2025 Gems & Gemology

Gem News International

by Kwanreun Lawanwong and Ravenya Atchalak, GIA, Bangkok, and Emiko Yazawa, GIA, New York

What GIA’s New York and Bangkok team just published in the Summer 2025 issue of GIA's Gems & Gemology is surprising: hybrid akoya bead cultured pearls grown from crossbred mollusks — P. fucata (martensii) and P. radiata.

What is a Hybrid Akoya Bead Cultured Pearl?

A “hybrid,” in this case, means that two different but closely related pearl oyster species were crossbred to take advantage of their respective strengths. The P. radiata lineage tolerates warmer waters, which allows nacre to build more quickly, while still retaining the beauty associated with akoya. Out of this experiment came pearls with nacre thickness not just slightly improved, but truly exceptional for akoya!

Tap here to find out more,

and for the link to the Summer 2025 G&G.

Gary Roskin

Roskin Gem News Report

The Gemmological Association of Australia (GAA) has taken a giant leap this year with the launch of its Certificate in Opal Studies—its first comprehensive, online course dedicated exclusively to opal.

Far from being a rework of existing material, this is a completely new course built from the ground up, the product of more than six years and hundreds of hours of volunteer effort by the GAA supported by the Australian Opal Centre. As told by the Association, “This course is a world first… and expert-led.”

The GAA Certificate in Opal Studies course opened for enrolments this past February. The program delivers 11 structured modules that take opal enthusiasts from the fundamentals of opal’s structure and how we get play-of-color (POC), through classifications of the different varieties of opals, their localities around the world, the details for cutting, to valuation, ethics, and the realities of the marketplace.

After working through several of the modules, I can say unequivocally that it lives up to the praise it has already received. According to Ken Scarratt, Vice President, World Jewellery Confederation (CIBJO) and Dean of the CIBJO Academy, “The GAA Certificate in Opal Studies provides a titanic amount of opal gemmological knowledge. The program is thoroughly recommended.”

“Titanic.” Yes! Ken is right about that. This course is packed with genuine first-hand knowledge, images, and video, provided by the experts who mine, cut, and sell opal. And it’s a course that is enjoyable to work through. How often do you get to say that?

Tap here to read our full review of the GAA’s Certificate in Opal Studies.

The Gemological Institute of America (GIA) has announced that their research team in Gaborone, Botswana — joined by Tom Moses, GIA Executive Vice President and Chief Research and Laboratory Officer, and Dr. Wuyi Wang, GIA Vice President of Research and Development — examined "the Motswedi," a massive 2,488.32-carat rough diamond recovered last year at Lucara’s Karowe mine.

What makes this rough diamond so important is that it's the world’s second-largest gem-quality rough diamond crystal ever found — and the largest still in existence.

“This is undoubtedly a diamond of great historical importance,” said Moses. “I have been fortunate to examine many significant, large and very rare diamonds, but I have never seen a gem-quality diamond of nearly this size.”

Discovered in August 2024, it weighed 2,492 carats at recovery and now tips the scale at 2,488.32 carats (≈1.10 pounds, or 0.5 kilograms). Its Setswana name, “Motswedi” — meaning “water spring” — was chosen through a national competition in Botswana. The stone ranks just behind the legendary 3,106-carat Cullinan diamond, unearthed in South Africa more than a century ago.

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“It is a Type IIa diamond of remarkable size with exceptional gemological qualities.” - GIA

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We know what you are thinking.

You are thinking, "If it's a Type IIa, with little or no perceptible nitrogen, then why does it look brown?"

Tap here for the full story, so far, about the world's second largest gem quality rough diamond!

On a Personal Note:

This is just a quick note — and a list — of all the presentations we managed to catch while at CONVERGE, GIA’s Symposium joined with AGS’s Conclave in Carlsbad, California, September 7–10.

Sunday, September 7 was a full day of tours. We spent the afternoon at GIA’s Carlsbad campus, where our guide, led us through an incredible behind the scenes tour of the gem lab. Having once worked in the GIA lab myself, it was impressive to see how much it has grown — and just as surprising to see how much has remained familiar.

The “GIA Museum” displays now extend throughout the main building, and if you plan a visit to GIA, that alone could keep your attention all day! Unfortunately, there was more on our schedule.

Back at Converge (the Omni Resort), the evening opened with a meet & greet with GIA’s new president, Pritesh Patel. It was an extraordinary chance not only to meet face-to-face with members of GIA’s corporate team, but also to reconnect with old friends.

Educational Sessions

We’ll be sharing highlights of the many sessions we attended on Monday, Tuesday, and Wednesday very soon. In the meantime, here’s the list of sessions we were able to attend. 

Tap here to check the list of sessions we attended.



Gary Roskin

Roskin Gem News Report

It was Tuesday evening, September 9, at CONVERGE, when everyone in attendance rose to their feet to honor Al Gilbertson, CG—the 2025 recipient of the American Gem Society’s highest distinction, the Robert M. Shipley Award^®.

The award recognizes Gilbertson’s lifetime of excellence in gemological research, education, and service to the industry.

“Al’s ability to bridge scientific precision with an understanding of diamond beauty has helped elevate our industry,” said Katherine Bodoh, CEO of the American Gem Society. “We are deeply grateful for his contributions and proud to honor him.”

In 2000, Gilbertson joined GIA as a researcher. He is one of the inventors of GIA’s cut grading system for round brilliant diamonds, and his name appears on several of the patents related to that system. He is part of the GIA team studying the influence of proportions and other factors on the appearance of fancy-shaped diamonds, working toward the development of a cut grading system for those shapes.

“Al’s impact on the gemological field is profound,” said Susan Jacques of the Gemological Institute of America (GIA), who presented the award. “His work is at the heart of how we evaluate the quality of a diamond’s cut. He brings curiosity, precision, and an enduring passion for excellence to every project, and his legacy will continue to guide gemological science for generations to come.”

Tap here to learn more about Al Gilbertson, and to see all past recipients in attendance for this important award!

Gary Roskin

Roskin Gem News Report

A week ago, the World Federation of Diamond Bourses (WFDB) posted a short promotional video on Instagram titled “Diamonds should be made by nature, not by Mike.”

The video introduces us to “Mike,” a fictional factory worker shoveling coal into a kitchen-size microwave oven to grow thousands of “lab-grown” synthetic diamonds. A young woman narrator tells us that “Mike-made” goods are not romantic, while natural diamonds—born of the earth, with “timeless charm”—are heirlooms she can pass down to her children, “not another copy from Mike’s giant machine.”

It’s lighthearted, tongue-in-cheek, and stamped with the disclaimer “dramatized for effect.” Still, it raises a bigger question: is this the right way to market natural diamonds?

Tap here to watch the short video, and to read the WFDB response, as well as what others are saying!

Gary Roskin

Roskin Gem News Report

Starting October 1, 2025, GIT—the Gem and Jewelry Institute of Thailand’s gem testing laboratory—will be updating the way it words its reports to better line up with CIBJO, the World Jewellery Confederation, and to keep things "clear and transparent."

Returning to Gemological Science

As we have seen recently with France, and very soon with CIBJO, the GIT will modify its identification field, shifting from: “Laboratory-Grown (name)” to: “Synthetic (name)” ... so this means you will now see Synthetic Ruby, Synthetic Diamond, Synthetic Sapphire, etc.

What Stays the Same

For GIT, the terms “Laboratory-Grown” and “Laboratory-Created” aren’t going completely away. They’ll still appear in the comments section of the report, listed as alternative trade terms to “Synthetic.” CIBJO states that "at the upcoming Paris Congress, the commission will propose an amendment to restore exclusive use of 'synthetic' for all materials meeting the Blue Book definition, and eliminating the descriptive terms 'laboratory-grown' and 'laboratory-created' from all CIBJO nomenclature."

Why the Update?

GIT says that this change will:

• make reports clearer and easier to understand for consumers
• stay aligned with shifting global gemological standards
• keep transparency front and center across the trade

CIBJO will be announcing these - and more - changes at the Paris Congress, October 27-29, 2025.

Tap here to get all the details, includingthe CIBJO Coloured Stone Commission’s Report!