Assuit pieces from the 1920s are made of real silver or a silver copper alloy that was hammered around cotton net. During the 1920s pieces made from this technique were insanely popular as all things Egyptian caught the fancy of the Western markets because of the touring of the King Tut exhibit. These originate from the Assuit region of Egypt and have been produced since biblical times. You can still find them today but the original, antique and vintage ones are far heavier and completely hand done - the difference is apparent at a touch.
Over time the silver can darken and the cotton can yellow from age. If you want to try to attempt to bring them back to their original beauty this is how (though I personally love the patina of time on these pieces and choose not to clean mine.) Even if you too love the patina that normal age causes, you may come across a piece that is just too spotted or tarnished to wear. For those cases - this is the trick!
Rub the metal work with fresh squeezed lemon juice and then hang the piece out to dry. Do not hang it in direct sunshine as this will actually do the opposite of what you're after and tarnish the metalwork. Only try this on garments whose silver has been placed on a white net base, as it will bleach black threads and ruin your scarf. Take your time - use a light hand and do it a few times if needed. And to be super safe - do a patch test first!