An 18k white gold and coloured stone kinetic brooch
Disc-shaped brooch with two concave mouldings holding two spherical beads made from half amethyst and half chrysoprase (diameter ca. 11.05 cm) mounted on vertical staves. Removable brooch mountings with double-pin. Hallmarks: Fineness 750, maker's mark "B" in a circle. Diameter 7.3 cm. Weight ca. 31.94 g.
Friedrich Becker, Düsseldorf, circa 1966.
The differing weights of the two halves of the stone spheres create an imbalance causing them to twist when moved, with the complementary colours forming an interesting effect.
Private ownership, North Rhine-Westphalia. Purchased from the goldsmith.
Cf. Becker, Friedrich Becker, Schmuck, Kinetik, Objekte, Stuttgart 1997, p. 115, 1966.5 for a version of this piece with a fire opal and a chrysoprase in the Schmuckmuseum Pforzheim.