10-Carat Fancy Vivid Blue Diamond Expected to Sell for $20M
Dubbed the “Mediterranean Blue,” this “remarkably rare” diamond will be part of Sotheby’s May jewelry auction in Geneva.

“The Mediterranean Blue” will make its auction debut at Sotheby’s High Jewelry sale in Geneva on May 13, estimated to sell for about CHF 18 million ($20 million).
The diamond is classified as Type IIb and its color grade, fancy vivid blue, is the Gemological Institute of America’s highest possible color grading for a blue diamond.
According to GIA, only 0.3 percent of all diamonds submitted to the lab annually display a color that would be described as predominately blue, and of those, only a small number are fancy vivid weighing 10 carats or more.
“Like its namesake, the Mediterranean Blue is a symbol of nature’s eternal wonders. Its physical beauty, enhanced by the skill of a master cutter, is mesmerizing as is its blue color, so rarely seen,” GIA said.
“The attributes of the Mediterranean Blue, weighing 10.03 carats in the most coveted fancy-color range, are absolutely exemplary for a diamond.”
As for the shape, colored diamonds require careful planning to balance the largest possible size, the best clarity, and the most vibrant face-up color, Sotheby’s said.

The Mediterranean Blue is a cushion modified brilliant-cut diamond, the result of a six-month long planning and cutting process.
Sotheby’s said the diamond’s shape accentuates its saturation and places it in a “rarefied category,” even among the world’s most beautiful diamonds.
The 31.94-carat rough diamond that yielded The Mediterranean Blue was studied for more than a year after Petra Diamonds recovered it from the Cullinan mine in South Africa.
The mine has been the principal deposit to produce blues in more recent times, though with decreasing regularity, and it has yielded a number of famous diamonds.
Among them are the rough that yielded the 530-carat Great Star of Africa, the largest faceted colorless diamond in the world; The Blue Moon of Josephine, a 12.03-carat cushion-shaped internally flawless fancy vivid blue diamond that sold for $48.5 million at Sotheby’s Geneva in 2015; and the De Beers Blue, a 15.10-carat step-cut fancy vivid blue diamond, which sold for HK$451 million ($57.5 million) in 2022 at Sotheby’s Hong Kong.
The Mediterranean Blue will be unveiled April 8 at a special exhibition in Abu Dhabi, Sotheby’s first public exhibition in the United Arab Emirates’ capital city since 2009.

The event will take place at the Bassam Freiha Art Foundation, a nonprofit institution located on Saadiyat Island’s Cultural District.
Following the event, the diamond will be showcased in Taipei, Taiwan; Hong Kong; and New York before its exhibition and sale in Geneva in May.
“The Mediterranean Blue represents one of nature’s rarest gems. Any vivid blue diamond is a discovery worth celebrating, but one as entrancing as this, particularly being over 10 carats, is a newsworthy event,” said Quig Bruning, head of Sotheby’s Jewels, Americas, & EMEA.
“The Mediterranean Blue’s remarkable size, charming cushion-cut, and ocean-blue color places it in the rarefied company of some of the most important blue diamonds to come to market in recent years.”
The Latest

Jeffrey Zimmer's decades of leadership at Reeds Jewelers are defined by integrity, a love of sourcing gemstones, and a heart for community.

The holiday catalog for 2025 features never-before-seen images of more than 100 one-of-a-kind masterpieces.

The brand has released a second installment of its collection of traditional and non-traditional commitment heirlooms.

You deserve to know what you are selling–to protect your customers as well as your business and your reputation.

Corey rescued New England chain Day’s Jewelers, preserving its legacy with strong people skills, pragmatism, and a “get-it-done” attitude.


Charles Robinson Shay was sentenced to life in prison plus 120 years while his accomplice, Michael James McCormack, got 75 years.

The Museum of Arts and Design's new exhibition features 75 pieces by the designer, best known for her work in the “Black Panther” films.

The upcoming show provides savvy retailers with the opportunity to stock their cases with best sellers in advance of the holiday season.

Timepieces at Luxury will take place at The Venetian and, like Luxury, will be invitation-only for the first two days.

As chairman of Schwanke-Kasten Jewelers, Tom Dixon has been tasked with honoring the past and shaping the future of the family-run store.

Katty Villapando Lyte and Mica Rencher received a $10,000 grant for their business, Shimmer Culture LLC.

The parents of the Dallas Mavericks rookie bought their engagement ring at a Day’s store in Bangor, Maine, in 1997.

The UK-based brand sourced the gemstones, which are fully traceable, from an artisanal mining community in Tanzania.

The trio of Advent calendars include a version with 18-karat gold and lab-grown diamond jewelry in a red lacquer jewelry box.

Created in collaboration with Nymphenburg Porcelain, the lock is part of a four-piece collection that took two years to bring to fruition.

Jewelry industry veteran Alisa Bunger has taken on the role.

The company and industry leader’s two-decade tenure with De Beers will come to a close at the end of the month.

“The Winter Egg” set the world auction record for a Fabergé piece twice at previous Christie’s sales.

The company will pay 1.5x silver’s current spot price for each pound of silver oxide batteries submitted.

The line includes a “Shadow” series crafted exclusively for the new men’s offering and reimagined styles from the brand’s core collections.

The rough on offer was recovered from a newer area at the Montepuez mine.

The retailer’s new collection of engagement rings and fashion jewelry is set with natural diamonds that are traceable via blockchain.

The champagne colorway in her newest “Ombré” collection combines white and trendy brown diamonds, a departure from her usual vibrant hues.

Kosann partnered with the Museum of Fine Arts, Boston, to create a set of necklaces inspired by the artwork on samurai sword handguards.

Carlos Jose Hernandez and Joshua Zuazo face life in prison for the October 2024 murder of 72-year-old Detroit-area jeweler Hussein Murray.

The brand’s first high jewelry collection, “Tempest” plays with movement while calling to mind the folklore of the sea.

Proceeds from its jewelry raffle will go to a volunteer-run fire and rescue group in the Lightning Ridge area of New South Wales, Australia.