Haroldo Burle Marx, born in 1911, was younger than Roberto by two years. He became a specialist who excelled in his chosen métier: jewelry. He was an innovator in his fields, lapidary work and gemology, and a masterful independent, modernist jeweler. When Time magazine wrote about the Burle Marx brothers in 1967, Haroldo was described as the manufacturer of “Brazil's most exquisite jewelry”. Haroldo trained in gemology and lapidary work for four years, studied in Idar-Oberstein, the center of semi-precious stone cutting in Germany, and began making jewelry in the late 1940s. By 1954 he ran a jewelry workshop full time, employing Italian and Brazilian artisans. He owned a fashionable boutique selling fine jewels, on Rodolfo Dantas, Copacabana, in Rio de Janeiro.

As a jeweler, Haroldo’s jewelry prior to 1975 showed the influence of his brother but his style gradually evolved in a different direction. For him, gems were central, an ancient material, as much “a product of nature as clouds or trees,” as he told Connoisseur magazine in 1983. Haroldo’s gemstones were of a high quality and often perfectly matched and, the yellow gold became more often polished than stippled and textured, with clear borders. Often the gold has an unusual patina, denoting the use of silver as the main alloy. His jewels have symmetry and balance. Among jewelry collectors, Haroldo Burle Marx became a coveted name, known for avant-garde fine jewelry, rich in color and exquisite in construction.