Since the 1970s, the Amsterdam-based designer Ruudt Peters has challenged traditional definitions of adornment by pushing the boundaries of context, wearability, materials, and presentation in his pioneering and conceptual jewelry. As a respected artist and professor at prestigious European schools, including the Gerrit Rietveld Academie, Amsterdam, and the Konstfack University College of Arts, Crafts, and Design, Stockholm, Peters has had a profound influence on the development of contemporary jewelry. His work is an important addition to the Museum’s growing collection in this area. The structure of Peters’s brooch, consisting of 11 silver spheres connected by silver bars, is based on the Kabbalah’s tree of life, which illustrates the Sefirot, the channel of divine energy or life force. The spheres are themselves the Sefirot, each representing a named aspect of God. Shaddai is one of the aspects—or emanations— of God, meaning “Almighty.” The glass elements of this brooch suggest alchemical glass forms, such as retorts. Other brooches in the “Sefiroth” series incorporate diverse materials, including stones, iron ore, and polyester, making references to sexuality, the human body, and, as in Shaddai, laboratories. Both alchemy and the Kabbalah study the structure of the world, using symbol systems to investigate the nature of existence and of the soul. About the “Sefiroth” series, Peters explained, “The names all come from Kabbalah. . . . But I use names and descriptions quite associatively, in an open-minded way, not dogmatic at all. It is more like a vehicle, something I use to express my ideas and emotions about life” (see below Besten 2008). Unsigned. Unpublished. The “Sefiroth” series, which is ongoing, is published in Liesbeth den Besten, “Ruudt Peters: Jewelry Is My Laboratory,” Metalsmith, v. 28, no. 1, 2008, pp. 38–45; and Jorunn Veiteberg, Sefiroth: Ruudt Peters, Nijmegen, the Netherlands: Galerie Marzee, 2006. See also www.ruudtpeters.nl.