Miyajima Magnetism

As I recall, it has a very narrow body when viewed on end.  Perhaps this is the reason its magnetic field is so evident when you bring ferrous materials near it.  But I guarantee you it's normal and/or perhaps exaggerated by a magnetized coil.  Why not carefully demag it and see what happens?  (I would consult the importer, Robin Wyatt, I think, before going ahead with that.)  However, generally a magnetized coil adds only a tiny bit to the field generated by the permanent magnet that makes the thing work as a transducer.

How would you be able to know if it is "abnormally magnetized".  As others have said, it contains a tiny but very powerful magnet or maybe a pair of magnets, by definition.  These produce a field that pervades the structure and evidently extends outside the confines of the body.  This is not at all unusual.  My Ortofon MC2000 will grab a screwdriver right out of my hands (and crush its own cantilever, if I'm not careful.)  Could the coil have become magnetized, due to its proximity to the magnet(s)?  (That's the magnetic field we try to get rid of when we demag an MC.) Yes, but the magnitude of that field would be tiny and not externally detectable, in my opinion.  If you're still concerned, ask the importer.