Jeff Liebermann wrote on Fri, 01 Mar 2013 18:47:40 -0800:

I also heated some of the white stuff on a microscope slide. It melted
like plastic (burning my fingers in the process). The white stuff also
disolved nicely in acetone.

Hi Jeff,

Those were fantastic pictures. I always assumed it was mold, but, now,
I must rethink 'what' it is.

I don't remember trying acetone, but, my screwdrivers still have a
hint of the white stuff from years past, so I will try that to see.

Thank you very much for the wonderful experimental work. You're in
the top 1% of all people who THINK on this planet!