1960s Ruby Diamond Platinum Dome Ring 6.5This vintage dome ring, circa 1960s, is made of solid platinum and features a bold geometric design set with a total of 1. 83 carats of French cut rubies. At the center, the ring is accented by three types of diamonds: 0. 52 carats of princess cut, 0. 32 carats of trapezoid cut, and 1. 36 carats of baguette cut diamonds. The diamond and ruby arrangement is precision set within a dome shaped platinum band stamped PT900, along with the carat weights for