CollectionsOct 05, 2026
Sorellina Writes Another Love Letter for ‘Postscript’ CollectionThe fine jewelry brand has expanded the collection that debuted at Couture with four new designs based on its most popular styles.
AuctionsAug 23, 2017
4-Carat Fancy Blue Diamond to Top Bonhams London’s Sale
The stone, headlining the Fine Jewellery sale Sept. 20, could sell for as much as $1.9 million.
This 4-carat pear-shaped fancy intense blue diamond will be the top lot at Bonhams London’s upcoming Fine Jewellery sale.
London--The highlight of Bonhams London’s upcoming fine jewelry sale will be a fancy intense blue diamond weighing 4.03 carats.
Pink and blue diamonds have been dominating the auction scene of late, with a number of them setting auction records, including The CTF Pink and the Oppenheimer Blue.
In fact, colored diamonds have increased in value, on average, by 100 percent over the past decade, with blue stones showing the strongest growth over the past 12 months at 5.5 percent, according to the Knight Frank Luxury Investment Index based on data from the Fancy Color Research Foundation.
When the pear-shaped blue diamond hits the auction block at Bonhams Sept. 20 after having been in a private collection in the U.K. for the past three decades, it is expected to sell for between $1.5 million and $1.9 million.
Meanwhile, the sale will feature 188 additional lots, including a selection of white and colored diamonds, sapphires from Kashmir, Burma and Sri Lanka, signed jewelry from Cartier and Van Cleef & Arpels and the private collection of Anglo-Italian designer Andrew Grima, the largest private collection of jewelry from the designer ever to go to auction.
The No. 2 lot of the sale is a fancy colored diamond brooch featuring a 4.83-carat square step-cut fancy gray-blue diamond with fancy dark brown-greenish yellow step-cut diamonds on either side--weighing 2.51 carats and 2.38 carats, and a suspended pear-shaped fancy pink diamond drop weighing 1.90 carats. It could garner between $834,000 and $1.1 million.
Following this piece is a Kashmir sapphire single-stone ring of 9.61 carats. The octagonal step-cut sapphire has no indications of heating, Bonhams said, and is estimated to sell for between $642,000 and $899,000.
This mid-20th century brooch featuring fancy colored diamonds is estimated to sell for as much as $1.1 million.
Another signed Cartier piece in the sale: these Art Deco diamond clip brooches circa 1935, estimated at between $51,300 and $77,000
This Cartier emerald and diamond bracelet dates from the 1960s and is expected to sell in the range of $64,200 to $89,900 next month.
This old-cut marquise diamond weighing 4.61 carats is D in color, VVS2 clarity and potentially flawless. It is expected to sell for as much as $128,400 next month.
A Kashmir sapphire ring, weighing 9.61 carats, expected to sell for between $642,000 and $899,000
Also among the top lots will be a piece perfect for old-cut diamond lovers: A 4.61 carat old marquise-cut type IIb diamond single-stone ring that could sell for between $102,700 and $128,400.
Bonhams will also be auctioning a number of signed pieces from Cartier as part of its sale.
This includes a pair of Art Deco diamond clip brooches circa 1935, estimated at between $51,300 and $77,000, and, adding more color to the sale, an emerald and diamond bracelet by Cartier. It features a series of alternating step- and octagonal-cut emeralds, accented on both sides by brilliant-cut diamonds, and has a pre-sale estimate of $64,200 to $89,900.
Full details of the lots to be auctioned at Bonhams London September Fine Jewellery sale will be put
Editors' Picks
Sponsored by
online at the end of this month.
More on Auctions
The Latest
SourcingOct 05, 2026
Bruce Bridges Joins CIBJO BoardThe AGTA president was elected for a two-year term on the board of directors.
SourcingOct 02, 2026
De Beers, National Geographic Society Renew Okavango Eternal Partnership The partnership, a pledge to protect Africa’s Okavango River Basin, has been extended for an additional five years.
Brought to you by
Meet Gemology’s Next Generation Microscope: GIA® Gemolite® NXT Professional EditionExperience gemstones with greater precision and comfort than ever before.
MajorsOct 02, 2026
Pandora Opens New $150M Manufacturing Facility in VietnamThe new facility, its first outside of Thailand, will boost its manufacturing capacity by 50 percent.
Weekly QuizOct 01, 2026
This Week’s QuizTest your jewelry news knowledge by answering these questions.
TrendsOct 02, 2026
Hearts On Fire Celebrates 30th Anniversary With Heart PendantThe special-edition “Dream” pendant, our Piece of the Week, was created to mark Hearts On Fire’s 30-year milestone with 30 diamonds.
CrimeOct 01, 2026
Police Looking for 4 Suspects in $600K Smash-and-Grab RobberyDubai Jewelers in Springfield, Virginia, was once again the target of an armed robbery.
Brought to you by
Your Piece Could Be the One Editors Talk AboutSubmit your pieces for a chance to win in this year's competition.
SurveysOct 01, 2026
Rolex Ranks Among Most Recommended Brands in US, Survey Says YouGov’s 2026 U.S. Most Recommended Brands report’s out, and a fast-fashion giant is sitting at No. 1 while Rolex is just shy of the top 5.
SourcingOct 01, 2026
Columbia Gem House Opens ‘Cutting Toward Change’ FundraiserProceeds from its jewelry raffle will benefit an organization working in India to combat silicosis, a lung disease affecting stone cutters.
TrendsOct 01, 2026
Carolina Hurricanes’ Championship Ring Reveals Hidden Hockey Puck PendantThe rings, crafted by Jason of Beverly Hills, celebrate the hockey team’s Stanley Cup win with design elements that honor its traditions.
TrendsOct 01, 2026
Amanda’s Style File: October’s Color Range This roundup of birthstone jewelry for October features vibrant tourmalines and opals with personality.
SourcingSep 30, 2026
Botswana’s President, De Beers CEO Say Diamond Demand Is RecoveringPresident Duma Boko spoke at back-to-back events in the city last week, touting Botswana’s stability and the diamond “bounceback.”
CollectionsSep 30, 2026
Oscar Heyman’s Holiday Book Is ‘A Living Archive’ The catalog showcases 112 new, one-of-a-kind pieces amid highlights from the jeweler’s historic archive.
SourcingSep 30, 2026
Gemfields Posts $98.5M Loss, Writes Down Value of Ruby MineIts Montepuez Ruby Mining operation in Mozambique, which is not yielding enough high-quality rubies, has taken a $125 million hit.
SurveysSep 30, 2026
Consumer Confidence Falls to 12-Year Low in SeptemberThose surveyed were worried about the present and the future, with write-in responses mentioning high oil and gas prices.
Events & AwardsSep 30, 2026
Jewelers of America, JA New York to Host Networking EventThe event will take place on the evening of Oct. 26 in New York City.
IndependentsSep 29, 2026
Christy Bromberg, Longtime Gift Buyer for Underwood Jewelers, Dies at 68She is remembered for her joie de vivre, upbeat personality, genuine interest in other people, and love of the Alabama Crimson Tide.
Events & AwardsSep 29, 2026
Matt Stuller to Receive 2027 Gem Award for Lifetime AchievementThe founder and executive chairman of Stuller Inc. is being honored for his impact on the jewelry industry at the 25th annual Gem Awards.
ColumnistsSep 29, 2026
Your Holiday Marketing Has a Bridal Blind SpotDecember is the most popular month to propose, and jewelers need to keep that in mind when planning their holiday marketing.
CollectionsSep 28, 2026
De Beers London Drops Water-Inspired High Jewelry Collection“Vibrations” features several firsts for De Beers’ high jewelry, including the use of chalcedony and diamonds sourced from artisanal miners.
CollectionsSep 28, 2026
Jessica McCormack Turns to Classic Motif for New CollectionThe “Bows” collection features three interpretations of the bow motif designed with Georgian and Victorian influences.
Events & AwardsSep 28, 2026
Guy Borenstein, Troy Underwood Among the Professionals Honored at AGS Conclave 2026The American Gem Society recognized industry members, one Guild, and a law enforcement official for their contributions to jewelry.
FinancialsSep 28, 2026
Instappraise, Jewelers Mutual Look to Simplify Jewelry InsuranceThrough a new system integration, customers can now receive instant personal jewelry insurance quotes at the time of appraisal.
WatchesSep 25, 2026
Smaller Rolex Watches Showing Strength on Secondary Market, Data ShowsFive of the 10 fastest-appreciating Rolex models on Bob’s Watches were Datejust 31 or Lady Datejust watches.
MajorsSep 25, 2026
Sherwood Family Buys Back Daniel’s Jewelers from Private EquityThe Sherwood family and AJS Creations CEO Tejas Shah purchased the jewelry chain back from Palladium Equity Partners.
Lab-GrownSep 25, 2026
Brilliant Earth Collabs with Elizabeth Taylor Estate on Jewelry Collection“The Elizabeth Taylor Collection” uses lab-grown diamonds and gemstones in contemporary designs inspired by the icon.
