Interlocking G Station Necklace

So I bought the matching bracelet for my finance two years ago and he’s worn it daily since. Still is in pristine condition even though he never takes it off (so it’s exposed to sweat, lotion, water, etc). Two weeks ago, I bought this matching necklace for him. He’s only worn it like 4 times (when not wearing he keeps it hanging up) and today he showed me it and was like “is it supposed to look black and dirty like this? My bracelet doesn’t”. The picture doesn’t really do it justice; nearly like 70% of it is black. I have other sterling silver jewelry that gets looking like this, but only after not wearing it for months. Again, this necklace is only like two weeks old and had only been worn a handful of times. Maybe it’s cleanable with polish, but seems insane to me that for this price especially, and because the matching bracelet doesn’t have this issue even after years.. that it would get this way this fast. So if you get this necklace, make sure you wear it daily so it doesn’t tarnish.. otherwise be prepared to spend like half an hour cleaning it before wearing each time.