Shiny copper(?) particles on my engine block drain plugs

[skisailpaddle]

Winterizing my 1999 4.3GL engine today. While draining raw water I noticed in addition to the normal sand/rust that collects in the plug cavity, this year there are bright particles in and on the plug. They are shiny and kind of look like tiny flakes of copper. At least I don't think there have been bright particles in past years, but maybe I just never noticed.

Thanks for any thoughts on what I'm looking at here... piston rings self destructing? boat is panning for gold?? Thanks.

 

[jimi]

Might be wear particles from the pipe threads?