Antonio Bianco, Who Teased Luster and Light From Diamonds

Whenever Antonio Bianco started singing at his workbench, it meant that the lump of carbon he had spent months transforming into a world-class diamond was nearly finished. Hoda Esphahani, an executive of the diamond company for which Mr. Bianco did much of his work, used to listen for that sound.Ms. Esphahani, the president of Safdico USA, recalled in an interview in the company’s New York offices on Monday. “And when he was singing opera, I knew that the stone was almost done, and we’d have great results.”

Mr. Bianco, his colleagues said, was a Stradivari of stones, one of the most renowned diamond cutters in the world. For more than 30 years he worked in blissful anonymity in New York’s diamond district, cutting some of the largest, rarest and most valuable stones of his time — stones important enough to have their own names. The diamonds Mr. Bianco cut are owned by some of the world’s most prominent collectors, among them Hollywood film stars and crowned heads of state.

Mr. Bianco, familiarly known as Nino, died of cancer on June 15 at Memorial Sloan-Kettering Cancer Center in Manhattan, his wife, Caterina, said. He was 57 and lived in Bridgewater, N.J.

Among master diamond cutters, Mr. Bianco was a quiet eminence. He was known in particular for his ability to look at the dull, shapeless surface of a rough stone and discern the finished diamond gleaming within, waiting to be liberated. Major diamond dealers often flew him across the world at a moment’s notice to examine stones they were considering buying.

“Nino was a star,” Laurence Graff, the billionaire diamond dealer from London for whom Mr. Bianco also cut, said by telephone from South Africa this month. “There are very few people left in the industry that have that type of skill.”

Mr. Bianco was among the tiny handful of cutters entrusted with the world’s largest and most unusually colored diamonds, both of which present great challenges to even an accomplished artisan.

“Very large diamonds are usually cut in Antwerp,” Ettagale Blauer, the New York editor of New York Diamonds, a trade magazine, said in a telephone interview this month. “And in the New York diamond-cutting industry, which has shrunk like clothes washed in hot water, he was one of the very few” to handle the biggest stones.

A round-cut 5-carat diamond is a little smaller than a dime. Most master cutters pass their entire careers handling diamonds no bigger than 20 to 50 carats — more or less the size of a quarter. For most cutters, a 100-carat stone is beyond contemplation.

Over his career, Mr. Bianco cut about half a dozen diamonds of 100 carats or more. Several of these were for Safdico, the South African Diamond Corporation. Among them were the diamonds known as the “Dream” and the “Golden Star, ” both cushion-cut vivid yellow stones, and the “Flame,” a pear-shaped white diamond nearly the size of a man’s nose. Each is worth tens of millions of dollars, Ms. Esphahani said. Finished, Mr. Bianco’s stones made their way to Graff Diamonds, where they were set into lavish pieces of jewelry.