Hello Lee, thanks for taking the time to write in....
18K white gold was introduced around 1915; it was the perfect imitation of the more expensive platinum. During WWII platinum was restricted and diverted away from jewelry making and directed towards accelerating munitions:-(
OK. the heart will be the maker's mark, the c could be part of the maker's mark, not sure. Is the letter c inside the heart, or is the heart just a heart, no letters, or numbers inside?
A light blue stone and white gold, uhmmmm.....the ring sounds beautiful! Have you tested the stone?
