Platonic Solids - Octahedron
The Octahedron has 8 equilateral triangular faces, 6 points and 12 edges. It is two 4 sided pyramids base to base. Its dual is the cube which has 8 points and 6 faces. It is the air element. The shape of some oxygen atom and the oxygen nucleus. The shape of 30,000 pyramids around the world with another one upside down below ground, the shape of many crystals.