A Papal sapphire, gold and enamel ring, early 19th century, designed as a cushion-shaped sapphire in

A Papal sapphire, gold and enamel ring, early 19th century, designed as a cushion-shaped sapphire in a gold collet of scrolled design, the reverse of the setting engraved with a papal tiara and enamelled with the coat of arms of Pope Pius VII (1742-1823), to a gold band, size S1/2, case with 'Ecclesiastial Art Exhibition' sticker, numbered 83

Provenance:
By repute, owned by Pope Pius VII (1742-1823), gifted to Napoleon Bonaparte while Pius VII was held at Fontainebleau, and later in the possession of the Borghese family.
Purchased from Giorgio Sangiorgi in Rome by the Countess of Cavan circa 1893/4
Thence by descent

Accompanied by a handwritten receipt from G.Sangiorgi, Rome, a handwritten letter detailing the ring's history, a handwritten card bequeathing it 'to my son Edward if he is a faithful priest to his faith in Jesus Christ', dated 1893, and a further handwritten letter explaining the iconography of Pius VII's coat of arms.