A polyhedron that is homeomorphic to a bitorus, a surface of genus 2 that can be visualize...
A polyhedron that is homeomorphic to a torus; for this polyhedron Euler’s relation does ...
A crystal of flourite, that has the shape of a regular octahedron.The image appears in the...
We find the cubes in nature, for example, in a crystal of cubic pyrite. The image has been...
Crystals of quartz, Madagascar. The image appears in the book Il ritmo delle forme - The r...
from "fragments of topology"