1950's Mid-Century Diamond Engagement Ring in 14k1950s Mid Century Diamond Engagement Ring in 14k. This lovely Mid Century engagement ring features a . 84 carat Old European cut diamond that is set in 14 karat yellow gold. The primary stone is set with four (4) prongs and the . 12 carats of bezel set accent stones are set in white gold, creating a beautiful two tone look on its face. From the side profile you can see that each stone has plenty of space for light to enter and enhance the sparkle.