User blog comment:Lord Loss/Monster Hunter Theory... Blog/@comment-5043481-20130202132942/@comment-6005381-20130202210238

Wrong wrong wrong. If you need more rare monster bones or ore nothing is better than the expand pickaxe.

Back to the actual question, I personally beleive that the head of the pick is made from some rare mimicing, radioactive substance which when energy is applied (by the force of your hunter's strike) emittes enough radioactive particals to balance it with watever it collides with.