Vintage Men's elegant .50ct "Diamond" ring sz10.25

Vintage Men's elegant 1/2ct "Diamond" ring gold plated sz 10.25 If this ring were real it'd be a beauty! Yellow gold plating, which has some chipping on the shank, and a tiny bit on the top. looks just fine from more than a few inches away. My pics are done at 5x magnification so you can see imperfections clearly I'm not sure what the stone is, probably just glass. I do know it's not a real diamond, lol inside shank is marked 18kt HGER (18kt heavy gold electroplate)