Cohen discusses the evolution of Citizen’s light-powered technology, the brand’s cross-generational appeal, and tariffs.
Johnny Kneller, an Expert on the Exceptional, Dies at 75
He was a close friend and business partner of Laurence Graff, who described him as “the greatest diamond dealer I have ever known.”

He was 75.
Kneller was born in 1946 in Prague, then in Czechoslovakia. He was the son of diamond trader who specialized in large stones.
Kneller grew up in Antwerp and followed in his father’s footsteps, eventually becoming an expert on big diamonds and polishing “countless” important rough stones, according to information provided by his son-in-law, Yves Alexis.
This includes the 603-carat Lesotho Promise, the 709-carat Peace Diamond, and the 1,109-carat Lesedi La Rona.
“He really loved the stones,” Alexis said. “[He loved] the material, to see the color, appreciate the cut, life and sparkle.”
Kneller was also one of the first diamond manufacturers to forge a “true alliance” with an extremely well-known high-end jeweler—Laurence Graff.
The two formed their partnership in the late 1990s, with Kneller bringing the high-end jeweler in as a partner at Safdico, the diamond manufacturing firm Kneller and Brian Gutkin started in the ‘80s.
In a statement shared with National Jeweler, Graff described Kneller as his best friend and business partner. The two were friends for five decades and traveled the world together for their diamond manufacturing business.
Graff said Kneller was a great partner with a vast, almost unparalleled knowledge of both rough and polished diamonds.
He had a “uncanny” way of finding exceptional gems, whether rough or polished, that ended up in Graff stores around the world.
Outside of the diamond business, both men also shared an interest in fine art. Graff said while Kneller had knowledge of art history that spanned decades, he was a collector of contemporary pieces.
The two had regular Sunday morning chats about diamond mines, production and manufacturing, as well as what works of art were up for sale.
“I will miss him immensely,” Graff said. “I loved him as family. A special intellectual, reserved, kind and considerate man, he lived and breathed diamonds all his life. For me, he was the greatest diamond dealer I have ever known.”
Kneller is survived by his wife, Delly; two daughters, Katya and Julie; and six grandchildren.
The Latest


“Essentially Human: On Sales and Salespeople" reveals the underlying human traits and behaviors of the most successful sales professionals.

The collection features symbols of love, luck, and light, based on the story of Queen Cassandane and Cyrus the Great of Persia.

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

It’s the third scholarship to be launched as part of the partnership to help appraisers advance their professional credentials.


The deadline for entries in the jewelry design competition has been extended to April 3.

Wiley said the project will give scientists worldwide access to the American Museum of Natural’s History renowned mineral collection.

Every jeweler faces the same challenge: helping customers protect what they love. Here’s the solution designed for today’s jewelry business.

The “Flower Puff” collection looks to beaded flower friendship bracelets from childhood, turning the silhouette into nostalgic fine jewelry.

Set for April 2, the webinar will discuss how the jewelry industry can address the workforce gap.

Bayer, founder of Lisa Bayer Designs, is remembered as “a bright light in every room.”

The highest-grossing lot was a Tiffany & Co. ring set with a flawless, emerald-cut diamond of 10 carats.

Former Sotheby’s executive Tom Heap has taken on the London-based role.

The group of women allegedly robbed two Catbird stores and one Gorjana location on the afternoon of March 9.

Movado CEO Efraim Grinberg noted continued strength in the fashion watch and accessible luxury segments in the U.S.

After celebrating 25 years in 2025, the campaign marks a new chapter for the jewelry brand with the message that “Identity Creates Value.”

Couture and Time to Watches announced the watch brands, from big names to independents, attendees will see at the show.

Plus, why Saks Global’s bankruptcy may have given Bloomingdale’s an edge.

The flawless, Type IIa stone is estimated to achieve up to $2.8 million at the auction house’s high jewelry sale in April.

Costume designer Kate Hawley wore three archival Tiffany & Co. brooches, our Pieces of the Week, while accepting her first Oscar.

The jewelry retailer announced changes to its store network and brand portfolio during its fourth-quarter earnings call.

From a weaker labor market to inflation, NRF Chief Economist Mark Mathews gave insight on what retailers can expect this year.

The historic stone, which sold at Elmwood’s in London, is the largest white diamond to be offered on the U.K. market in more than a decade.

Three-time Grammy award-winning artist Nelly is set to perform at the annual event at Tao Beach in Las Vegas on May 31.

The model and fashion editor’s gold evening bags were the top lots at the London sale, going for more than $25,000 each.

Fresh off winning the David Yurman Gem Awards Grant, Nelson discusses the ring that launched his career and his plans for the future.

The “stunning” Type IIb stone was found via x-ray technology at its Karowe mine in Botswana.




















