> I share R. S. Gwynn's bafflement.  However, the Greek word
> "sideros" meant both "iron" and "star".  (I could have sworn
> somebody pointed that out in this connection on this list, but
> I can't find it in the archives.)

 

Sorry, "sideros" (long e) is indeed Greek for iron, but the other
word I was thinking of is apparently Latin "sidus" (long i), star
or constellation, plural "sidera".  The etymological authorities
I looked at (too late!) don't seem to think the words are
related.  If Shade had this in mind, it would have been something
of a stretch.

 

Jerry Friedman