The suite of jewellery was commissioned from Margaret de Patta during the 1930's by the vendor's mother who lived on the West Coast of America, using emeralds she had purchased in Colombia.
Margaret de Patta studied painting and sculpture at the Academy of Fine Arts in San Diego (1921-1923), the California School of Fine Arts in San Francisco (1923-1925) and the Art Students League in New York (1926-1929). She turned her attention to jewellery in 1929 developing her innovative skills to a high standard with Lazlo Moholy-Nagy at the School of Design in Chicago in the 1940's. She was influenced by Picasso and became a seminal figure in American jewellery with her bold use of new materials and techniques.
Refer: Jewellery, Makers, Motifs, History, Techniques published by Thames & Hudson page 158.