A wonderfully unusual Swiss-made fob watch in 18ct gold, dating to circa 1900. The miniature watch fits into a separate diamond-set outer case, transforming it into a wristwatch. It is this clever convertible design that makes the piece particularly special.

The quality is apparent in the small details, from the guilloché enamelled chapter ring and crisp black Roman numerals to the old-cut diamonds surrounding the dial when cased. The richly jewelled outer case gives the watch the presence of a piece of fine jewellery, while preserving the charm of the miniature fob within.

A rare and beautifully considered piece, with real appeal for anyone drawn to unusual antique watches. Its combination of decorative detail and ingenious construction is what sets it apart.

The details

• Origin: Swiss-made
• Period: Circa 1900, late nineteenth to early twentieth century
• Material: 18ct gold; outer case marked “18k”
• Design: Miniature fob watch with an additional outer case for conversion to a wristwatch
• Dial: White, with a guilloché enamelled chapter ring and black Roman numerals
• Diamonds: 22 old-cut diamonds, estimated at approximately 0.10ct each
• Estimated total diamond weight: 2.20cts
• Movement: Cylinder movement
• Diameter when cased: 2.8cm
• Weight: 29g
• Case reference: 2353