18KT and Platinum Ring, 14KT Heart Diamond Solitaire

I wear these with my previously posted band, the other 18kt/plat band I was told is from the 20's, I haven't been able to find that symbol anywhere, I have my doubts about it's antiquity, but still a pretty ring that matches my other 2 beauties. The heart diamond is more recent, a company called magic glo manufactured, it is .57 ct, about an SI2, because of crystallization inclusions. nice white colour. I would be lost without my set of rings!