Regarding Bill Shirley's favorite dry lubricant [MMD 980904], I have a
few comments.  I also have a bottle of the stuff that I have saved for
many years.  I am almost certain that it is finely ground mica.  It may
have been discontinued due to its abrasive effects.  I would not use it
on anything soft, such as leather.

If this lubricant is needed for certain purposes, it probably could be
made from mica from some other source or might be even available as
powdered mica from some sort of industrial supplier.

Spencer Chase