Johnny Kneller, an Expert on the Exceptional, Dies at 75

Antwerp—Johnny Kneller, a man who “lived and breathed diamonds all his life,” succumbed to cancer on Jan. 20.

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.