These extremely rare bands are called "skeletals" - the first example dates from 1659, and this one was made not long after in 1731. A full skeleton and other death-themed emblems are meant to drive home the brevity of life. An hourglass represents time passing, and gravedigger's tools are a poignant memento mori symbol. There's significant loss to the black enamel, which we actually like, because it means that you can truly wear this ring (if you're a size 8.5, that is - it cannot be resized.) A perfect example with intact enamel would be unwearable without great care. This one? I mean, it is a treasure, but go ahead and stack it. A similar one (in pristine condition) has been deaccessioned by the Museum of London and is available from the venerable Symbolic & Chase; another example can be found in the British Museum. I cannot overstate how few of these are in circulation.
Inside are the death details: "Reb Man ob 20 Sep 1731 aet 63". FG makers mark.
MATERIALS: 22k gold (tests), black enamel
AGE: dedicated in 1731
CONDITION: Very good - surface wear to the gold and enamel commensurate with age and use
SIZE: size 8.5, cannot be resized; 4.2mm shank