In the natural environment, regular polyhedra can be found in the form of crystals (minerals). The form of the tetrahedron is transmitted by antimony sodium sulfate.
Even a rough diamond clearly conveys the shape of an octahedron. After grinding, the stone corresponds exactly to the geometric shape of the octahedron.
The structure of the perovskite molecule, the chemical formula is CaTiO3, exactly corresponds to the correct polyhedron.
Spinel. The stone got its name from the Latin "sp'inella" - a small thorn.
Cube - single crystal combines the crystals of salt NaCl.
The pyrite crystal (pyrite FeS) is in the form of a dodecahedron. Pyrite (from the Greek. "Pir" - fire) - sulphurous iron or pyritic sulfur, the most common mineral from the group of sulphides. The size of pyrite crystals reaches several centimeters.