The ring is Italian and bears the crossed keys mark of Rome, circa. 1815 - 1870.
The intaglio dates to the 1st- 2nd century AD.
Ring size R 1/2 UK / 9 US / 59 EU.
The carnelian intaglio is carved with inward facing portrait profiles of a husband and wife, each wearing laurel crowns. The gem is set in a rub over setting with a fine split shank. There is a French ‘ET’ duty mark to the reverse of the shank.