Cartier Portico Mystery Clock No. 6 – the last and ultimate Art Deco masterpiece created by Cartier. Coming to Sotheby’s Important Watches, Geneva, 9 November. Mystery clocks, first introduced by Cartier in 1912, are among the most enchanting creations in the history of horology. Hitting the auction block at #SothebysGeneva this November, Portico Mystery Clock No. 6 is the last of only six produced between 1923 and 1925, and it was once owned by the charismatic German businessman and art collector Gunter Sachs. No. 6 is crafted from black-enameled yellow gold and rock crystal. The dial, made of rock crystal, reveals the “floating” hands, framed by a bezel set with onyx and diamonds. A rock crystal shi-shi (Chinese guardian lion) crowns the piece – making No. 6 the only Portico clock with this distinctive feature. In every generation, a handful of figures define the zeitgeist of their era. Gunter Sachs was one of them – a man who counted Coco Chanel, Salvador Dalí, and Andy Warhol am...