This is a special Estate napkin ring. It is lovingly inscribed from her Godmother: 6-12-1919. It has the initials P.M.D. It is also hallmarked with proper English hallmarks. It is 1 3/4" in diameter and 1" tall and weighs 47.5 grams.
It appears more scratched in the photos than in person, but certainly was special and treasured over the years. No dings or repairs.