ART NOUVEAU STYLE LADY BROOCH IN WHITE METAL

I do have trouble trying to decide what date some of my pieces of vintage jewellery were made.  This brooch is an example.  I am sure it is not an original Art Nouveau piece but it has the correct push pull clasp for the period.  I am also sure it is not modern - it is probably silver plated on brass (due to the weight).  I think there were quite a lot of Art Nouveau style pieces made in the 1970's - but this is just a guess!  Anyway it is an impressive brooch - probably made in France (where it was recently bought) and it is in good condition.  It measures approx 3 x 2 inches.  See my web site - www.gillianhorsup - price £75.  Reference 2761 C8/38