Issue 9, December 21, 2022
The very latest gem news...
Last Week
The winner last week was our feature story on the 10.67-carat Fancy Grey emerald cut diamond that sold in Sotheby's Magnificent Jewels auction December 7th.
You loved it as much as we did.

And so did the trades! There's an old saying, "Imitation is the sincerest form of flattery." There were several trade reports that picked up on our excitement. Thank you! We are flattered.

And if you are still curious about this particular stone, there's even more to the story. You can read about it here in our category, "a personal note." Link below.

[If you missed our original report last week on this incredible diamond, we'll give you that link below, too.]
10.67 carat Fancy Grey
Extremely rare Art Deco diamond ring. Circa 1925.

Original Content
Original content for this week includes three gem and jewelry images with captions for our gem-files. These include a December birthstone - Tanzanite, along with Natural Pearls, and Cultured South Seas Pearls. It's the end of the year and so we thought "What better way to sweeten up your newsletter visuals than by giving you a selection of gemmy eye-candy?" It's our way to help you unwind after a busy holiday season. (See the Gem features below.)

After an interesting email conversation with one of our subscribers (who just happens to be an expert in sapphires), we checked in with GIA's Shane McClure, Global Director of Colored Stone Services, and one of the authors of "An Update on Sapphires with Unstable Color." Is it heated? Is it not heated? Is bright incandescent light the same as bright LED light? What happens to the sapphire when exposed to UV? What exactly is the test for color stability? After discussions on these questions and more, we have updated our feature: "Is it Padparadscha, or not?"
We have also updated our report on the "Top Ten Results: Fancy Color Diamonds," simply adding a slightly better description for one of the more unique pieces, the Fancy Vivid Blue diamond snake ring. It sold for $2.1 million, so we felt a better description of the diamond was in order.
Well, now this was interesting. We posted a press release last week that talked about a project in Tanzania that claims to be making efforts in establishing an ethical supply chain.

This produced several serious conversations with subscribers who are very concerned about how our industry seems to be divided on just how an ethical supply chain can evolve, or even what it should look like. And that's just the tip of the iceberg. There's so much to discuss and so much to do.

Don't lose that thought. We will return to this topic after the new year.

The FACETS Show in Sri Lanka!
I know we have been focused on Tucson, but for those who need Sri Lankan goods, do not forget to visit the FACETS show in Colombo in just two and a half weeks! (See post at the bottom of the newsletter.)

Next Week
Happy Holidays! We are taking the week off.
We will see you next in the new year - Wednesday January 4th, 2023!

We have reached a new milestone, with now over 16,000 subscribers!
Those who wish to support the Roskin Gem News Report by placing an Ad, please request a media kit. Our contact information is below.

Read On ... Issue 9 of the new Roskin Gem News Report Newsletter. 

Gary Roskin
The Rise of the House of Asscher
that 10.67 carat Fancy Grey Diamond
Gary Roskin -
Roskin Gem News Report -
December 14, 2022

The Rise of the House of Asscher
JCK Magazine:
September 1, 2001 
by Gary Roskin

In my feature story for JCK Magazine, 2001 September, “the Rise of the House of Asscher,” [a twist on one of Edgar Allen Poe’s most famous works of 1839, “The Fall of the House of Usher,” later made into a movie in 1960 starring Vincent Price], the Asscher Cut diamond, a 1902 patented step cut design, the first step cut for diamond, reached popularity in the early 1920s – the Art Deco period. The 10.67 Fancy Grey emerald cut from Sotheby's auction was shown to me as an Art Deco ring, circa 1925, with the facet arrangement of the patented Asscher Cut; big "strong" corners, tall crown (higher crown angles), small table (56%), and large culet.

Stephen Hofer, author of the most important reference on the subject, "Collecting and Classifying Fancy Coloured Diamonds," has written specifically about why this grey diamond is so important.

If you missed our original report last week, here is that link.
Journal of Gemmology 38/no.4
The latest issue of the Journal is out.

Heat treated pink to red Spinel, Emerald mining in Brazil, several features on responsible practices, a host of conferences reviewed, and …

Demantoid from Iran

“Demantoid from Kerman Province in south-east Iran was investigated using microscopy, spectroscopy (optical absorption, FTIR and Raman), chemical analysis (EDXRF and LA-ICP-TOF-MS) and magnetic susceptibility measurements. The samples were transparent to semi-transparent and commonly contained acicular chrysotile inclusions. Their spectroscopic and chemical properties were consistent with demantoid from serpentinite host rock.

The samples ranged from yellowish green to deep green, depending on Cr and Fe content. These two elements are also largely responsible for the material’s paramagnetic susceptibility. Our samples contained relatively high concentrations of the trace elements Cr, Ge, Ni and Co. Comparison with available chemical data on serpentinite-hosted demantoid from the literature suggests that Iranian demantoid can be separated from stones of other localities.”

Tanzanite with Faceted Diamond Beads
Tanzanite, a blue/purple color variety of Zoisite, is found only in the Merelani [Mererani] Hills of northeastern Tanzania [near Mount Kilimanjaro].

While much of the gem material is heated to enhance or even produce this beautiful mix of blue and purple, there are tanzanites that come out of the ground this color - unheated by heat treaters – natural color.

Natural Pearls

Pearls that are created by Mother Nature (and the oyster, of course) are called “Natural Pearls.” There is no (intentional) human intervention of any kind before the pearl is harvested.

Here is a five strand necklace of all natural pearls. Originated from the Persian Gulf, their cream color, beautifully matched spherical shapes, and high luster (you can see me and my camera in each pearl) makes this an exquisite example of what is possible.

The Westward Look Show
Some of the finest minerals in all of Tucson!
2023 – February 3 – 6

About the Westward Look Show

“With literally hundreds of places available to visit and see great minerals from around the world, the Westward Look Show has become one of the most important places to visit to see the best mineral collections available.

The Westward Look Show features some of the finest dealers in the business with mineral specimens you won’t be able to see anywhere else.

There are hosted weekend events that are designed to educate and entertain individuals of all experience levels. Best of all, the show is free (except for the minerals, of course!).”

Is it a Padparadscha, or not?
... an update.
Gary Roskin – 
Roskin Gem News Report – 
December 20, 2022 – 

As we mentioned above, we have made some clarifications in our original post based upon our conversation with Shane McClure at GIA.

Is it a Padparadscha, or not?

[This feature has been updated: December 20, 2022]

"GIA Observes Unusual Color Change in Sapphires During Color Stability Testing"
… and what is Tenebrescence?

Above – Image copyright GIA, Press Release

Over the past several years (2018/2019 till today), more and more sapphires have undergone color stability testing as gem dealers discover sapphires with color instability … elementary, they change from pink to pink-orange (padparadscha), and then back again to pink.  

This color change is NOT due to changing light sources, e.g. incandescent to fluorescent and seeing an alexandrite-like color change. No, this is caused by exposure to ultraviolet light (where it gains yellow and/or orange) and then reverts back by heat [not heat treatment], lack of light, or strong incandescent light. This is called Tenebrescence.

South Seas Cultured Pearls
South Seas cultured pearls are (most commonly) grown by implanting a mother of pearl (MOP) spherical bead inside a large oyster (species varies based upon where in the South Seas the oyster is being raised). The nacre build up around the MOP sphere is greater in the warm waters of the South Seas, hence the larger finished cultured pearl. In the image above, the golden cultured pearl is from Indonesia, whereas the baroque white cultured pearl is from Australia.

Baroque cultured pearls were once considered ...

AGA announces new Governing Board
Gary Roskin - 
Roskin Gem News Report - 
December 20, 2022 - 

AGA announces new Governing Board to serve 2023 to 2026 term.
The Accredited Gemologists Association (AGA) voting members have elected its 2023-2026 Board of Governors. The eleven-member all-volunteer Board includes representative leadership and experience from across the gem and jewelry industry, and AGA Membership. 

The upcoming 2023-2026 AGA Board of Governors term adds distinguished gemologists Gary A. Roskin, Martin Fuller and Alberto Scarani to serve as new Governors, and sees the return of seven current board members, reelected and returning to serve. Gina D’Onofrio, Antoinette Matlins, and Donna Hawrelko will return as AGA Governors. AGA Executive offices will include Teri Brossmer to serve a second term as President, with Vice-President Cigdem Lule, PhD, Secretary, Adam Ostrow, and Treasurer, Heidi Harders, and AGA’s immediate past-president Stuart Robertson.

“It has been an honor to serve as AGA President for the past 3 years,” writes Terri Brossmer, AGA President, who will stay on for another 3-year term. “I am proud of the AGA Board for implementing creative ways to thrive and serve the AGA community, despite the challenges of a worldwide Pandemic. I am particularly pleased that the AGA just witnessed the largest group of members answer our call to stand for election to the AGA board that the association has seen in decades. Clearly, AGA’s growth and expanded educational programs, and advocacy for industry standards, is inspiring more and more members to volunteer time to AGA. I look forward to working with the new AGA Board to advance our existing initiatives and to develop new and exciting ways to serve our membership and the gemological community.”

AGA also extends their appreciation to the retiring board members Richard Hughes, Ted Irwin, and Raymond Mason for their selfless dedication, time, and leadership serving AGA in recent years.

The New Board

The new Board will be sworn in during the 2023 AGA Tucson Gemological Conference on Wednesday, February 1, 2023, and recognized later that evening at the AGA Gala dinner and Bonanno Award presentation.

Join AGA in welcoming these individuals and thanking them for their service.
Tickets to attend the conference and/or gala are available online.

Top Ten Results: Fancy Color Diamonds
Gary Roskin –
Roskin Gem News Report –
December 07, 2022 –

[This feature has been updated: December 20, 2022]

Rahul Kadakia, International Head of Jewelry, Christie’s, sent us over the top ten list from last evening’s auction. Seven of the ten top sellers were fancy color diamonds.

This included the blue, a 31.62 carat, VVS1 (potentially internally flawless), Fancy Blue pear shape, mounted in a necklace set with colorless and pink diamond melee, front and back. 

Other fancy color diamonds making the top ten were a 107 carat Fancy Yellow cushion by Graff, a Fancy Intense Blue oval, 2.21 carats, a 104 carat Fancy Intense Yellow modified pear shape, a Fancy Vivid Blue rose cut, a pair of earrings set with fancy color heart shape diamonds, and “The DeBeers Yellow,” a 13.75 carat Fancy Vivid Yellow internally flawless emerald cut.

Thank you

Well, this has been one interesting year!

I never would have imagined the turn of events that brought me back to the Roskin Gem News Report, but I am so happy that they did!

If you like what you are reading, then please pass this along to everyone you believe will feel the same way.

Thank you all for your support!
Stay informed and keep in touch. I'd like to know where you've been and what gems you've seen.

I will continue to post features on the website, so feel free to log on to the Roskin Gem News Magazine any time at

If you would like to contribute, or you have read something somewhere that you feel would be perfect to share with the community, then please feel free to contact me directly at

I will see you again SOON!


Stay safe and stay healthy!

Gary Roskin
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