Structure of Sodalite, Pedro Isidoro, Master Thesis, Açores University.
Mineral Sodalite Na4Al3Si3O12Cl, belongs to group 218
P-43n, with a cP lattice and parameter a = 8.91 Angstrom.
Sodalite has SiO4 and AlO4 tetrahedra present in approximately
equal numbers, forming four-fold or six-fold rings.
Discovered in 1806 in Greenland, Sodalite is a
common constituent of lapis lazuli. Gnome
on Ubuntu 10.04. Size: 92,042 bytes.
Structure of Beryl, Pedro Isidoro, Master Thesis, Açores University.
Mineral Beryl Be3Al2(SiO3)6, belongs to group 192 P6/mcc, with
a hP lattice and parameters a = 9.206 and c = 9.205 Angstrom. Its
structural dominant feature are the hexagonal rings of six SiO4
tetrahedra, forming empty columns along the c axis. Pure Beryl is
colorless, but it occurs in a diversity of colors. Red Beryl is
extremely rare.
Gnome on Ubuntu 10.04. Size: 104,665 bytes.
Using Atom->Select to select the atoms inside a graphic region.
With Object->Select dialogs, lists of objects can be selected for
all objects supported by GAMGI, using many different properties,
logical operations, selecting objects by region or picking them
directly, on a hierarchical tree or graphic area. These lists
can then be manipulated using the other task dialogs.
The structure represented is an ice clathrate, type I, 8M - 46H2O,
with 46 water molecules tetrahedrally bonded, forming cages with
8 simple molecular species M trapped inside. Gnome on Ubuntu 10.04.
Size: 141,466 bytes.
With Plane->Create and then Plane->List, arbitrary lists of plane
families can be easily created, either as poles, traces in stereographic
projections, or as polygons in the other cell representations. The same
functionality is available for crystallographic directions. The image
shows a stereographic projection of hexagonal Wurtzite ZnS, with all planes
from (-3 -3- 3) to (3 3 3), represented both as poles and traces, with Euler
angles at 45, 45, 45 degrees. Gnome on Ubuntu 10.04. Size: 301,332 bytes.