Prince Rainier proposed at her family home in East Falls, Pennsylvania over Christmas 1955 with an eternity band featuring heirloom red rubies and diamonds meant to echo Monaco's flag. While filming High Society he later presented a Cartier ring with a 10.48‑carat emerald‑cut center and two bezel‑set baguette side stones on a platinum band. That ring was estimated at $4 million then — roughly $38.8 million today.
Mel Ferrer proposed in August 1954 in a garden overlooking Lake Lucerne with a trio of bands: yellow gold, rose gold and a 1.5‑carat diamond baguette eternity band. Hepburn wore them stacked or separately; their current estimated value is about $10,047.