You have at least two other threads on this same topic, since this is the original thread you should close the others.
Amber (if genuine) comes from areas around the Baltic Sea, think Poland, Lithuania etc. so you might want to try some Google searches on silver hallmarks in those areas.
Both of the links I included in my last post allow you to search hallmarks my country - given StrphanieLynn’s comment, that might be a good place to start. I think one of those sites also hosts a discussion forum.
There are thousands - maybe hundreds of thousands - of hallmarks out there. Sometimes you get lucky when you post a question like this and someone recognizes the hallmark, or it’s one that’s easily researched. Most of the time though the best we can offer is tools you can use to delve deeper in your your own research... and even then you might come up empty-handed. But you’ll probably learn a bit along the way!
Good luck with your research, and enjoy your lovely pendant!