With total sales exceeding 60 million Swiss Francs (over $70 million), Christie’s Magnificent Jewels auction at the Four Seasons Hotel des Bergues in Geneva did not disappoint. While the much-anticipated Golconda blue diamond—rumored to be worth upwards of $100 million—was notably absent, the evening still delivered a compelling show of market strength.
The spotlight belonged to the “big four” — emeralds, rubies, sapphires, and diamonds — with blue diamonds taking the top two spots. A fantastic collection of JAR embarrassed the sales estimates, reaffirming the house’s collectability. Blue sapphires performed well, emeralds held steady, and rubies — though few — soared past high estimates with ease.
The catalog was a who’s who of historic and modern maisons: Harry Winston, Van Cleef & Arpels, Graff, Bulgari, Buccellati, Belperron, Marcus & Co., Fabergé (from the early 1900’s), and David Webb all made appearances, each offering exceptional pieces. The depth and diversity of the evening made it impossible to spotlight all of the highlights — but suffice it to say, collectors had plenty to compete for.
From a Gemologist’s Eye
The Auction’s Most Unexpected Takeaways
Gemologically Intriguing
Let’s begin with JAR. Looking closely at the six pieces we’re highlighting (from a dozen offered), you’ll notice several key gemological details are missing — like the obvious … gemstone weights! Or disclosure… the origin of color for both diamonds and colored gemstones. A few of the JAR jewels contain black diamonds with only the note: “not tested for natural colour.” There were also two important sapphire rings where country of origin was undeterminable! And, quite surprisingly, a remarkable diamond necklace—visually substantial—that checks the trifecta: no listed weights, no colors, no clarities. Nothing at all!
Moving to the other 100+ items up for sale, there was a magnificent emerald and diamond brooch (seen here) that ties in nicely to our newsletter feature, “Emerald Filler Clarity: New Price Guides for Clarity-Enhanced Emeralds Now in the GemGuide.” While these emeralds are too large to be priced within the current guides, the result — CHF 900,000 [$1,000,000!] — may offer insight into how clarity enhancement (Minor and Moderate Filling) impacted the bidding.
And of course, we can’t forget the auction’s top two lots: the 6-carat VVS2 Fancy Deep Blue and the 3-carat VVS2 Fancy Vivid Blue. Both appear to be potentially Internally Flawless with minor recutting – so we will take a closer look at those too!
And finally, we will compare the two diamond necklaces: the one with no provenance but full grading on the larger stones, and the JAR necklace — showstopping, yet offered with no grading at all. An interesting comparison worth unpacking.
All of that — and more — awaits! Let’s get started!
JAR
Among the highlights of the Magnificent Jewels auction was “A Bouquet Of Gems: A Superb Collection of Jewels by JAR” – one of the largest and most important private collections of 21 works by the visionary designer, Joel Arthur Rosenthal.
1. A magnificent expandable bangle from JAR, expanding far beyond the high sale estimate!
Leading the high mark was Lot #44, DIAMOND ‘APRICOT BLOSSOM’ BANGLE.
Estimate: CHF 280,000 – CHF 550,000
Price realized: CHF 2,374,250
JAR DIAMOND ‘APRICOT BLOSSOM’ Expandable BANGLE
Round diamonds, reddish orange and yellow enamel, blackened silver, yellow gold (French mark) and bronze, signed JAR, with a pink JAR case.
GemNote: No sizes or weights, and no total weight.
2. HERE IT IS! AN EXTRAORDINARY JAR DIAMOND NECKLACE
Estimate: CHF 500,000 – CHF 700,000
Price realized: CHF 2,162,500
Sixteen (16) Old-cut and numerous round brilliant cut diamonds, 18 karat rose gold and blackened silver (French marks), signed JAR
Size/Dimensions: 40.5 cm long
Gross weight: 77.1 grams
Gemological Details:
First of all, there are number of very important details missing, like the weights of each of the sixteen large old cut style diamonds [note the very small tables, slightly large culets, and misshapen facets and outlines, all signs of an older cut, an older style of cutting], and the diamond melee surrounds in each link. Clarities and colors would certainly be interesting as we assume that there should wear from age, and maybe some improvement with minor recuttings. We also see hints of cape yellows, browns and maybe even some pinks.
Turn the piece over and you realize that craftsmanship extends to the backside. Truly a one-of-a-kind important and valuable piece.
GemNote: You can see the larger culets and wide pavilion main facets here from the backside.
3. JAR SAPPHIRE AND DIAMOND RING
Estimate: CHF 110,000 – CHF 160,000
Price realized: CHF 441,000
Oval-shaped mixed cut sapphire, round sapphires and diamonds, set in platinum (French marks), signed JAR, Paris, and comes with a pink fitted JAR case.
GemNote: Center sapphire comes with a Gübelin Gem Lab report, 2025, report no. 25030045, with a declared weight of 13.10 carats, no indications of heating, with an Information Sheet on Sapphires. In this particular case, and again for another JAR sapphire ring, country of origin was undeterminable by the laboratory. According to the laboratory report, indications are that the sapphire could have originated from either Sri Lanka or Madagascar.
4. JAR MULTI-GEM CHAIN NECKLACE
Estimate: CHF 220,000 – CHF 320,000
Price realized: CHF 352,800
JAR MULTI-GEM CHAIN NECKLACE
Round brown diamonds, emeralds, tourmalines, tsavorite and spessartine garnets, peridots, purple, orange, pink sapphires and sapphires, topazes, fire opals, rubies, pink and purple spinels, amethysts, and aquamarines, 18 karat rose gold and blackened silver, signed JAR, and comes with the pink JAR case
Size/Dimensions: inner circumference of 35.6 cm
GemNote: The auction catalogue includes this statement: “Please note that the coloured diamonds have not been tested for natural colour.”
For any gemologist and appraiser, that naturally raises the question—why not? When a lot sells for $424,000, you’d think confirmation of natural color would be part of the listed details. Rahul Kadakia, international head of jewellery at Christie’s, answers the question this way… “Joel’s jewels are all about design and color, which is what clients appreciate the most.”
5. JAR MULTI-GEM ‘PANSY’ EARRINGS
Estimate: CHF 130,000 – CHF 200,000
Price realized: CHF 327,600
JAR MULTI-GEM ‘PANSY’ EARRINGS
Round sapphires, purple, orange and yellow sapphires, tsavorite and spessartine garnets, diamonds and black diamonds, blackened silver and 18k yellow gold (French marks), signed JAR, Paris, pink JAR case
Size/Dimensions: 2.9 cm high
Gross weight: 21.2 grams
GemNote: As expected, there is no disclosure of origin of color for the colored gemstones, and this statement was once again listed: “Please note that the black diamond has not been tested for natural colour.”
BLUE DIAMONDS
EXCEPTIONAL COLOURED DIAMOND, DIAMOND AND RUBY BALLERINA RING, MOUNTED BY BOUCHERON
6.24 carats, Emerald Cut, Fancy Deep Blue
Estimate: CHF 4,500,000 – CHF 6,500,000
Price realized: CHF 10,640,000
Fancy deep blue emerald-cut diamond of 6.24 carats, round rubies, baguette-cut diamonds, set in platinum, and signed Monture Boucheron.
Central diamond comes with a GIA diamond grading report, 2025, report no. 2235537515:
6.24 carats
Fancy Deep Blue, natural colour
VVS2 clarity, potentially Internally Flawless
Type IIb
GemNote:
“POTENTIAL”
In diamond grading, the term potential means that the clarity characteristics responsible for a VVS2 grade can be removed through minor recutting or repolishing. If those features are successfully eliminated—and no new ones are introduced in the process—the diamond could achieve an Internally Flawless or even Flawless grade.
When a diamond is considered to have potential, the client can request a working diagram that maps out the location of all existing clarity characteristics.
The fact that a working diagram is offered also reflects the lab’s opinion that any weight loss from the cutting process isn’t likely to bring the diamond below a key carat threshold.
Below is the working diagram for this diamond.
RARE GRAFF COLOURED DIAMOND AND DIAMOND RING
Estimate: CHF 2,700,000 – CHF 3,700,000
Price realized: CHF 4,885,000
Oval-shaped fancy vivid blue diamond weighing 3.68 carats, pear-shaped diamonds, set in platinum, signed Graff.
The central diamond was graded by GIA, and is accompanied by a GIA diamond grading report, no. 5231562997: 3.68 carats, Fancy Vivid Blue, natural colour, VVS2 clarity, Type IIb – colored by Boron.
GemNote:
According to the report, the clarity characteristics are chip and feather. These are surface reaching and can be removed with little weight. POTENTIAL? For all we know, this diamond could be Potential, recutting to Internally Flawless. There appears to be enough weight, and there doesn’t appear to be any inclusions that cannot be removed with minor recutting/repolishing. The new owner simply needs to ask the lab for a working diagram.
IMPORTANT HARRY WINSTON BURMESE RUBY AND DIAMOND RING
Estimate: CHF 450,000 – CHF 650,000
Price realized: CHF 3,493,500
Cushion-shaped ruby of 10.17 carats, round diamonds, 18k yellow gold, and comes with the blue Harry Winston case.
This fabulous ruby comes with two professional gemological reports – one, a Gübelin Gem Lab report, 2025, report no. 25030072: stating a declared weight of 10.17 carats, Burma (Myanmar), no indications of heating, Pigeon Blood, with Information Sheets on Rubies from Mogok, Burma and Unheated rubies, and with an important Appendix letter.
And two – an SSEF, Swiss Gemmological Laboratory report, 2025, report no. 145516: noting a 10.173 carats ruby, Burma (Myanmar), no indications of heating, Pigeon Blood, also with an Appendix letter stating the rare and exceptional qualities of this ruby.
GemNote: With origin so important here, both country and color, two professional gem labs have examined this ruby, and both agree. On occasion, gemstones of high caliber are accompanied by more than one report, two or three, and sometimes even four.
SAPPHIRE AND DIAMOND RING
Estimate: CHF 600,000 – CHF 800,000
Price realized: CHF 2,071,750
Cushion-shaped sapphire of 13.80 carats, tapered baguette-cut diamonds, set in platinum, 18k white and yellow gold (French marks)
GemNote: Again, an important gemstone like this Kashmir sapphire should have more than one gemological report.
1.) SSEF, 2025, report no. 146226: 13.801 carats, Kashmir, no indications of heating
2.) Gübelin Gem Lab, 2025, report no. 25040048: 13.80 carats, Kashmir, no indications of heating, Royal Blue, with Information Sheet on Unheated sapphires and Appendix letter stating the rarity of this sapphire
Auction Note: It is fairly common to see a prong missing, a stone missing, chipped enamel, anything that could have been caused from normal wear. Here, with this $2 million ring, we have a prong that needs repair. You would think …. but on the other hand, the seller can simply leave it to the buyer to decide if they want to keep the mounting or design something new. (Reminder: this is Harry Winston.)
The Potential Necklace!
IMPORTANT DIAMOND NECKLACE
Estimate: CHF 1,000,000 – CHF 1,500,000
Price realized: CHF 1,557,500
are graded Internally Flawless to VVS1. Those graded VVS1 are potential!
IMPORTANT DIAMOND NECKLACE
Eight (8) Emerald-cut diamonds of 10.61, 8.37, 5.13, 5.13, 4.42, 4.10, 3.16 and 3.10 carats, set with rectangular, pear-shaped and round brilliant cut diamonds, set in platinum, where the central section is detachable to form a bracelet, and the diamond pendant also detachable.
The necklace is accompanied by eight GIA diamond grading reports, 10.61 to 3.10 carats, all D colour, all Internally Flawless to VVS1 clarity (potentially Internally Flawless), 5 Type IIa and 3 Type Ia
GemNote: Isn’t it fascinating that you can have a necklace that is so important that all of the major diamonds have been professionally graded, sells for $1.9 million, and yet another diamond necklace, with noticeably larger diamonds, but no gemological reports, colors are not top color, clarities might be potential or improvable, but we do not know, where design is more important than gemology, sells for $2.6 million?
BULGARI EMERALD AND DIAMOND PENDENT BROOCH
Estimate: CHF 600,000 – CHF 1,000,000
Price realized: CHF 907,200
This magnificent brooch features two very large Colombian emeralds. On top, a buff-top sugarloaf weighing 43.55 carats, surrounded by pear shape, marquise shape, and round brilliant cut diamonds. Suspended below, a pear shape Colombian emerald weighing 24.84 carats, surrounded by graduated round brilliant cut diamonds. The pear shape pendant is detachable. Signed Bvlgari.
GemNote:
Enhancement Matters
Each emerald comes with its own Gübelin Gem Lab report. The 43.55 carat Colombian emerald shows minor clarity enhancement with a traditional filling material (oil-type). The 24.84 carat Colombian emerald shows moderate clarity enhancement with a traditional filling material (oil-type).
As we learned from the feature story above regarding new emerald pricing charts in the GemGuide, there is a pricing difference between minor and moderate clarity enhancement. The good news is that the enhancement was identified as an oil type, which is preferred over resin type fillers.
6. JAR DIAMOND AND COLOURED DIAMOND RING
Estimate: CHF 130,000 – CHF 200,000
Price realized: CHF 226,800
Last but not least in our JAR coverage is this standout diamond ring—featuring a 6.36 carat old-style cushion modified brilliant-cut diamond, notable for its shallow depth, large table (71%), and extremely large culet. It’s accented with round brilliant-cut black diamonds (again, not tested for color enhancement) and near-colorless round brilliant-cut diamonds, uniquely set upside down—tips up—in platinum and 18k yellow gold. Signed JAR, Paris, and yes, it comes in the iconic pink JAR case.
Fashion over Function?
Much like a pair of couture footwear—stunning, but not exactly built for long walks—this ring seems to favor artistry over wearability. One might imagine a note tucked in the box: “Avoid delicate fabrics” or “Fist-clenching not advised.” Practicality was likely never the point. This is jewelry as statement, as sculpture. Or, as Kadakia might remind us, “Joel’s jewels are all about design and color, which is what clients appreciate the most.”
GemNote: The center diamond comes with a 2025 GIA diamond grading report no. 5232531586: stating the weight as 6.36 carats, I colour, and VS1 clarity. You will find the dimensions on the report as well, seen here, or by going to www.GIA.edu and plugging the report number into GIA’s Report Check.
