Striking, large, Modernist sterling silver pin by preeminent Modernist jeweler, Sam Kramer (1913-1964). As stated in the excellent book, MODERNIST JEWELRY 1930-1960 by Marbeth Schon, Sam Kramer was one of the most significant American studio jewelers of the mid-20th century. He graduated from the University of Southern California and learned to work silver at Dave Heller, a jewelry manufacturing company in Pittsburgh. Moving to New York city, he enrolled in a gemology course at NYU. He opened his first studio in Greenwich Village, eventually relocating it to 29 West 8th St. The decor in his shop was quirky. Two cast bronze hands served as doorknobs. Other decorations included a plaster deer's head, a stone angel, swords and fencing masks. He studied Navajo and other Native American jewelry, as well as Mexican, Italian and French. Of his signature "mushroom" mark he said: "a mushroom grows in dark, gloomy places and my jewelry is often eerie and mysterious". This was a custom made piece. It is quite heavy (1 and 6/10 ounces) and features a deep red cabochon. It measures 2 3/4 inches by 1 3/4 inches and has a depth of 1/4 inch. Marked: "STERLING" along with Sam's "mushroom" mark. Excellent condition. A rare and elegant piece of Modernist jewelry history!