A CARTIER CITRINE, ONYX, JADE, SILVER AND DIAMOND 'MYSTERY CLOCK', CASE NO. 201207, CIRCA 1970S with manual movement, with facetted octagonal smoky quartz dial, diamond-set hands, bezel-set diamond hour markers, the dial within a jade border, with mother-of-pearl support banded with diamonds, the octagonal plinth of onyx, jade and sterling silver, marked on base with 925 standard, maker's mark Cartier Paris and case no. 201207, with winding keys, housed in a fitted red leather Cartier case; overall height: 25 cm (9 7/8 in.)