Zunyite Al13Si5O20(OH,F)18Cl is an aluminosilicate with hydroxyl and halogens. It is remarkable because it contains units of 5 silica tetrahedra (pentamers).
At top, above, is one of the silica pentamers. It consists of a central tetrahedron with additional tetrahedra joined to each vertex.
At bottom, above are clusters of aluminum polyhedra. There is a central tetrahedrally coordinated aluminum, with each vertex joined to three octahedra. At left bottom is a perspective view and at right a transparent view. The aluminum atoms are at the vertices of a distorted cuboctahedron (outlined in red).
Zunyite has tetrahedral symmetry. Above: view down one of the isometric axes. Red are hydrogen atoms in hydroxil ions. The vertices in the aluminum polyhedra may be occupied by oxygen, hydroxyl or halogens.
View along a unit cell diagonal.
Created 22 April 2013, Last Update 08 Jul 2013
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