Vintage Round Circle Pin Brooch Silver Tone Textured Etched Diamond Cut Design.  MCM ... I owned this pin back in 1968.  Purchased at Ben Franklin Store to wear for a Sunday Dress.  

This pin does not attract to a high power magnet.  It has been in my jewelry box for over 20 years.  I don't wear that much jewelry anymore since I retired.  

Measures 1 1/4 inches in diameter.  The back pin is straight and works like it should.