Tetrahedron
Without a doubt, this was the most difficult piece for me in the entire
certification class.  The purpose of this piece was to test our skills in
constructing a piece to exact specifications, working with dry PMC,
geometric symmetry, soldering findings and producing a mirror finish.

The finish was the most difficult.  I have done hand finishing in the past,
but not on something with this much surface area.  I spent a total of
about 8 hours on this piece and then had to go back and re-do some of
it after some of the solder from the pin back got on the front of the
piece.  Ugh!  

At least I can say that I learned a lot with this piece.