cylinder....
Well, assuming the spear pole shaft is basically cylinder, I would try to paint it with a SENMM effect.
There are some tips for that sort of thing in the article section, but here is the link to one by Chrispy..
http://www.coolminiornot.com/go.php?go=articlephp&aid=54&orderby=date&levels=99
I would think that Dark Elves\' spear shafts would be fashioned out of metal, not wood, so painting it like a dark reflective metal might be neat.
Good luck!!