Editing Octahedron (section)

==Octahedra in the physical world==

===Octahedra in nature===
[[Image:Fluorite octahedron.jpg|thumb|[[Fluorite]] octahedron.]]
* Natural crystals of [[diamond]], [[alum]] or [[fluorite]] are commonly octahedral, as the space-filling [[tetrahedral-octahedral honeycomb]].
* The plates of [[kamacite]] alloy in [[octahedrite]] [[meteorites]] are arranged paralleling the eight faces of an octahedron.
* Many metal ions [[Coordination chemistry|coordinate]] six ligands in an octahedral or [[Jahn–Teller effect|distorted]] octahedral configuration.
* [[Widmanstätten pattern]]s in [[nickel]]-[[iron]] [[crystal]]s

===Octahedra in art and culture===
[[Image:Rubiks snake octahedron.jpg|thumb|Two identically formed [[Rubik's Snake]]s can approximate an octahedron.]]
* Especially in [[roleplaying game]]s, this solid is known as a "d8", one of the more common [[dice#Polyhedral dice|polyhedral dice]].
* If each edge of an octahedron is replaced by a one-[[ohm (unit)|ohm]] [[resistor]], the resistance between opposite vertices is {{sfrac|1|2}} ohm, and that between adjacent vertices {{sfrac|5|12}} ohm.<ref>{{cite journal |last=Klein |first=Douglas J. |year=2002 |title=Resistance-Distance Sum Rules |journal=Croatica Chemica Acta |volume=75 |issue=2 |pages=633–649 |url=http://jagor.srce.hr/ccacaa/CCA-PDF/cca2002/v75-n2/CCA_75_2002_633_649_KLEIN.pdf |access-date=30 September 2006 |archive-url=https://web.archive.org/web/20070610165115/http://jagor.srce.hr/ccacaa/CCA-PDF/cca2002/v75-n2/CCA_75_2002_633_649_KLEIN.pdf |archive-date=10 June 2007 |url-status=dead }}</ref>
* Six musical notes can be arranged on the vertices of an octahedron in such a way that each edge represents a consonant dyad and each face represents a consonant triad; see [[hexany]].

===Tetrahedral octet truss===
A [[space frame]] of alternating tetrahedra and half-octahedra derived from the [[Tetrahedral-octahedral honeycomb]] was invented by [[Buckminster Fuller]] in the 1950s. It is commonly regarded as the strongest building structure for resisting [[cantilever]] stresses.