Collection of forms resulting from all the combinations of the Platonic and Catalan polyhedra
which characterize the m 3 5
icosahedral point group
Livio Zefiro
Dip.Te.Ris., Universita' di Genova, Italy
(E-mail address: livio.zefiro@fastwebnet.it)
Notes
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Tested with Internet Explorer 7, Mozilla Firefox 3, Opera 9.64 and
Google Chrome at 1024x768 and 1280x1024 pixels
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All the images have been generated by SHAPE 7.0, a software program for
drawing the morphology of crystals, distributed by Shape Software
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Hovering with the mouse on each image, the symbol of a pointer appears:
if your web browser is set up to visualize VRML files, by clicking with
the left button of the mouse it should be possible to visualize in a new
window the corresponding dynamic image, that can be enlarged, rotated,
shifted... Cortona 3D Viewer is a good Web3D visualizer that can be
downloaded from here:
at present it is working also with the updated versions of the main browsers.
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As already pointed out in two previous papers
[1,2], all the icosahedral compound forms, and in particular the ones belonging to the
holohedral m
3
5 point goup, can be
derived from seven single forms, corresponding to two Platonic and five Catalan polyhedra.
The two Platonic polyhedra are the dodecahedron and the icosahedron: both are
characterized by Miller's indices having a fixed value. The same holds true for the rhomb-triacontahedron,
a Catalan polyhedron dual of a quasi-regular Archimedean polyhedron, the icosidodecahedron.
Conversely, the indices of the other four forms can assume variable values, in the intervals defined in the following table.