By no means an authority on this, just 'thinking out loud' ....... hard to tell if what I'm seeing is a reflection of color or is there a coppery color showing through in some areas? If so, I'd say it's silver plate.
If someone isn't able to give you a bit of a start this would be the best place to post......
http://www.925-1000.com/forum/index.php (Just sign up and try the silver plate section of the forum first.)
Most searching you would do on marks will take you to their site. Fortunately they have a forum for just such inquiries.
Don't know why, but Egyptian keeps popping into my mind followed by Arabic. But like I said......I'm just winging it here