Vintage Modernist Gusterman's Sterling Silver Sculptural Brooch. The studio was founded in Georgetown, Colorado by Scandinavian immigrants Stig and Astrid Gusterman in 1950. This set is entirely handmade and signed with the mark used until 1964 It measures approx 4.3 cm in across. It weighs 32.4 grams. It is fully hallmarked with "Gusterman's, Georgetown, Sterling" plus their makers mark.