These jewels stood out at Bonhams’ sale of the cat-loving tech entrepreneur’s collection of objects depicting the feline form.
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

The fine jewelry brand has expanded the collection that debuted at Couture with four new designs based on its most popular styles.

The partnership, a pledge to protect Africa’s Okavango River Basin, has been extended for an additional five years.

Experience gemstones with greater precision and comfort than ever before.

The new facility, its first outside of Thailand, will boost its manufacturing capacity by 50 percent.


The special-edition “Dream” pendant, our Piece of the Week, was created to mark Hearts On Fire’s 30-year milestone with 30 diamonds.

Dubai Jewelers in Springfield, Virginia, was once again the target of an armed robbery.

Submit your pieces for a chance to win in this year's competition.

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.

Proceeds from its jewelry raffle will benefit an organization working in India to combat silicosis, a lung disease affecting stone cutters.

The rings, crafted by Jason of Beverly Hills, celebrate the hockey team’s Stanley Cup win with design elements that honor its traditions.

This roundup of birthstone jewelry for October features vibrant tourmalines and opals with personality.

President Duma Boko spoke at back-to-back events in the city last week, touting Botswana’s stability and the diamond “bounceback.”

The catalog showcases 112 new, one-of-a-kind pieces amid highlights from the jeweler’s historic archive.

Its Montepuez Ruby Mining operation in Mozambique, which is not yielding enough high-quality rubies, has taken a $125 million hit.

Those surveyed were worried about the present and the future, with write-in responses mentioning high oil and gas prices.

The event will take place on the evening of Oct. 26 in New York City.

She is remembered for her joie de vivre, upbeat personality, genuine interest in other people, and love of the Alabama Crimson Tide.

Online bidding is open now for Julien’s sale of items owned by the “Walk On By” singer, whose final album comes out this fall.

The founder and executive chairman of Stuller Inc. is being honored for his impact on the jewelry industry at the 25th annual Gem Awards.

December is the most popular month to propose, and jewelers need to keep that in mind when planning their holiday marketing.

Cat ladies of the jewelry world, unite. Sandy Lerner’s collection of cat jewelry and other objects is going up for auction Wednesday.

“Vibrations” features several firsts for De Beers’ high jewelry, including the use of chalcedony and diamonds sourced from artisanal miners.

The “Bows” collection features three interpretations of the bow motif designed with Georgian and Victorian influences.

The American Gem Society recognized industry members, one Guild, and a law enforcement official for their contributions to jewelry.

Through a new system integration, customers can now receive instant personal jewelry insurance quotes at the time of appraisal.

Five of the 10 fastest-appreciating Rolex models on Bob’s Watches were Datejust 31 or Lady Datejust watches.























