Vintage Retro Tiffany & Co. Diamond Engagement Ring in 14kThis charming Tiffanys engagement ring from the 1950s features a . 45 carat round brilliant cut diamond set in platinum on a 14 karat yellow gold band. Held by four thick platinum prongs, the diamond sits at the center of the split yellow gold shoulders to create a nice contrasting color palette. This darling ring has a special and distinguished quality along with its simple elegance.