Nelson Diamond Clock. Up until the 1970s, the Nelson office created many different items for the home, including the Bubble Lamps and the Ball Clock, which became icons of mid-century modern design.The Desk Clocks are available in a diverse range of shapes and materials. Equipped with high-quality quartz movements, they continue to offer a refreshing alternative to conventional clocks. High-quality quartz clock movement, 1.5 volt battery included. Brass, acrylic glass, polyurethane, solid walnut.