I think you would get more/better info by taking it a jeweler. The pictures are too blurry and without more information and details, I don't think anyone here can give you much help. Sorry.
If the ring is gold or silver it would mean it is 82.5% precious metal and 17.5% alloy. I have never seen it marked that way on gold jewelry but have on silver. You need to test it.
It is silver with 82.5% purity, a tad bit less pure than sterling silver, which is 92.5% pure. I had never heard of this purity before your post, but it is real according to some web postings.