Found this today walking across a parking lot. No stamp, but the stud is missing and as far as I know, that is where the stamp normally is. When looking at it, I noticed that it is not plated, as the color runs through it (see broken ends). It was also heavier than I would have expected for costume jewelry. It is not hollow and as small as it is, it weighs a fairly hefty 2.268 grams. I really need to buy a testing kit and now I have a good reason to do so. So, opinions on it, gold or no.