The verdict came in Werner Lippe's second murder trial; his first trial ended in February with a hung jury.
Prosecutors were hampered by the lack of any forensic evidence: No body, no bone fragments, no DNA.
But Lippe, of Cortlandt, confessed three times that he killed his 49-year-old wife, Faith, as they were in divorce proceedings.
On recorded statements, he said he knocked her out with a board, then burned her up in a backyard "burn barrel."
Lippe recanted those confessions, saying he made them up out of fear. He claimed it was impossible to destroy bones and teeth by burning.
The Lippes had two children.
"We now have a small piece of closure that will allow us to stop dwelling on Faith's death so we can start celebrating her life," Shari Caradonna, a cousin of the victim, said afterward.
The defendant showed no obvious reaction to the verdict.
One on of the recordings, Lippe told a friend that he reduced his wife to ashes.
"She doesn't exist anymore," he said. "They can't find her."
At both trials, Lippe said he learned when his mother was cremated that teeth and bones can't be burned to ash. He said he thought he would be exonerated when authorities realized his body-burning story couldn't be true.
"I came up with a story that I burned her because I know it is impossible for me or anyone in the world to burn a body (completely)," Lippe said.
He said the last time he saw his wife - Oct. 3, 2008 - she was being driven away from their home in a car he didn't recognize.
But prosecutors said Lippe, whose jewelry clients have included Donald Trump and Yoko Ono, could have disposed of his wife's bones and teeth with the acids he kept in his workshop at his home in Cortlandt, a town of about 40,000 residents just north of New York City.
He testified that he concocted a confession because he feared investigators were manufacturing evidence against him. He said his friend, James Learnihan, had promised the investigation would end if Lippe admitted the killing. He also said he had become fearful that Learnihan would hurt him if he didn't say what Learnihan wanted to hear.
"I wanted him off my back," Lippe said.
The prosecution revealed no major new evidence, forensic or otherwise, in the retrial. Prosecutor James O'Rourke said Lippe shouldn't "get a benefit" for getting rid of the body.
He described Faith Lippe as "the quintessential soccer mom and PTA mom" who cared for the couple's 14-year-old son and 12-year-old son.
By killing his wife, the prosecutor said, Lippe stood to gain $1.5 million he would lose in the divorce.
"He had the motive to kill her, he had the means, he had the opportunity and he had the know-how," O'Rourke said.