Georg Jensen Sphere Sterling Silver Black Onyx Cufflinks. 3533820. Sphere - With its perfect symmetry and luminous glow, like a magic crystal ball, Sphere dares us to imagine the future and charms us into dreaming of destinies beyond our control. These subtle sterling silver and black onyx cufflinks are part of the Georg Jenson Sphere range. The solid spheres of sterling silver create a unique gents accessory. Please see our website for further Georg Jenson products. Dimensions: 25 mm.