French, 64 mm, circa 1830
An extremely rare, decorative pocket watch key with cameo "Zeus and Hera"
Case: gilt brass, large carved oval medallion of sardonyx: the front side with the portrait of Zeus, the back side with the portrait of Zeus' wife and also sister Hera, ornamented frame with cornucopias.
This key is made of three-layered sardonyx, which lends itself admiration to the engravers' talent. They made good use of the alternating white and red-brown stripes of sardonyx, a variety of chalcedony.
Illustrated and described in: "The Keys of Time" by Yves Droz, France 2012, p. 84-85.