Israel mentioned last night that the five Platonic Solids were associated with five elements. We were discussing the superiority of the d12, but the idea of five elements does have an appeal to me, since our campaign featured a pantheon with five branches.
Here’s a nice page about the Platonic Solids from the book (or/and course) Geometry in Art and Architecture, dealing with the history of the Platonic Solids. Anders Sandberg writes in Spiritweb about Platonic Solids and Their Symmetries, covering their mystical correspondances.
Sort-of related are the Chinese Five Elements, which also have their own correspondances.