Claude Arpels (1911–1990) was the eldest son of Julien Arpels and a nephew of Estelle Arpels and Alfred Van Cleef. He became a partner in Van Cleef & Arpels in 1937, with his brothers Jacques and Pierre and his cousin Renée Puissant. With war approaching, his father sent him to Harvard so that he would be better prepared for American clients.
In 1939 he settled in New York and opened an office on the 31st floor of Rockefeller Center, at 630 Fifth Avenue, while the house took part in the New York World's Fair. A boutique in Palm Beach followed in 1940, and the flagship at 744 Fifth Avenue opened in 1940 (1942 in French Wikipedia). He spent most of his career running the American business, was president of Van Cleef & Arpels, and in 1969 opened the Beverly Hills store on Rodeo Drive. After the war he and his brothers ran the house as its second family generation.
His friendship with George Balanchine, co-founder of New York City Ballet, sparked the idea for Jewels, a ballet in three acts, Emeralds, Rubies and Diamonds, set to music by Fauré, Stravinsky and Tchaikovsky, which had its premiere in April 1967. With his brother Pierre he travelled in India in search of stones, journeys the house credits with its Indian-inspired pieces.
He died in Paris in October 1990, aged 79. His son, Claude Arpels Jr., joined the firm after his death and left in 1993; in 1999 the family sold 80% of the house to Richemont and the Florentine holding company Fingen.
Sources differ on the opening of 744 Fifth Avenue (1940 or 1942). His obituaries in the New York Times and Los Angeles Times are the main sources for his American career.