It''s a silver brooch with maker's mark W.J & S.
The first mark looks a little bit like a musical note, letter M or maybe some sort of harp. The second mark is a 925. The third mark looks a bit like a greek 'Tau' letter and is something I've never seen in silver before - I've attached an example of what it looks like below.
In terms of style, it's an Irish shamrock with green agate inlay. Many thanks!
