The royal’s trendsetting ring weighed over 10 carats and has an estimated value of $38.8 millionGrace Kelly on the set of 'High Society' in 1956.Credit: Getty ImagesThe GistGrace Kelly received a 10.48-carat diamond engagement ring from Prince Rainier of Monaco in 1955.The dazzling proposal piece and her other jewels were returned to her family upon her death in 1982.Her engagement ring last went on public display in 2016, on loan to the Cartier…