14k Yellow Gold Diamond Engagement/Promise Ring Size 3.5

14k Yellow Gold Diamond Engagement/Promise Ring Size 3.5. I am not a jeweler, but I would guess this diamond is approximately .25 carat. This ring is in great condition. There is one prong that doesn't go up over the diamond that I can see with my loupe. It is possible that a jeweler can fix this. I am discounting the price due to this fact. Tests as diamond and as 14k gold. D