An Art Deco diamond cocktail watch, circa 1930

The rectangular glass engraved with rose motifs at the corners, the dial displaying blue enamel Arabic numerals, to a bezel and lugs set with single-cut diamonds, decorated on one end with a course of French-cut sapphires and a line of onyx on the other, to a later expandable bracelet, diamonds approx. 0.40 carat total, movement signed Longines, numbered, Swiss assay mark, length 17.2cm