The soul, spirit, space, aether, even the universe and consciousness are concepts unified by the dodecahedron. Its the 4th platonic solid and has 12 faces (pentagons), 20 vertices (points), and 30 edges.
Your light body vehicle. Composed of two intersecting tetrahedrons it also can be seen as a 3D hexagram which just so happens to represent our heart chakra. Nested within it is the Octahedron which represents air. Connecting its points creates the Cube which represents earth.
The tetrahedron which represents Fire is the first 3D shape. Its the basic building block to everything. Its a great place to meditate. I like to call it a Zen Zone.