Art Deco Jade & Topaz Antique Sterling Silver Bar Pin

What a fabulous find this is!  Art Deco bar pin marked 925 and "M" with what appears to be a diamond over the top. I've been unable to identify this mark, which is clearly the maker's hallmark.  It is faux marcasite and the stones they used test as topaz on my gem tester.  They are a silvery opaque color -- clearly not rhinestones.  Gorgeous translucent jade stone as the centerpiece. 

The pin measures 2 inches long by 1/4 inch wide.

Elegant example of fine antique jewelry that would grace any collection.