Designed in the late 1920s-1930s by Cartier Paris, this mechanical pencil pendant necklace is composed of 18K gold, enamel and rose-cut diamonds. The reeded telescoping cylinder with bands of black champlevé enamel, base  incised with monogram "TMK" serving as a seal, and enclosing a mechanical pencil, with rose-cut diamond top, suspended from an enamel bail and black silk cord. A rare Cartier accessory created by one their exclusive expert workshops, this chic pencil pendant necklace with tis subtle sparkle is a streamlined example of utilitarian beauty.