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Hexagonal crystal system



   

In crystallography, the hexagonal crystal system is one of the 7 lattice point groups (see Hexagonal lattice). It has the same symmetry as a right prism with a hexagonal base. There is only one hexagonal Bravais lattice, which has six atoms per unit cell.

Graphite is an example of a crystal that crystallizes in the hexagonal crystal system.

Hexagonal arrangements have also been observed in systems of amphiphiles and constitutes one of the types of lipid polymorphism.

The point groups (crystal classes) that fall under this crystal system are listed below, followed by their representations in Hermann-Mauguin or international notation and Schoenflies notation, and mineral examples, if they exist.

name international Schoenflies example
dihexagonal bipyramidal \mathrm{\frac6mmm} D6h beryl
dihexagonal pyramidal \mathrm{6mm} \, C6v greenockite
hexagonal bipyramidal \mathrm{\frac6m} C6h apatite
hexagonal pyramidal \mathrm{6} \, C6 nepheline
hexagonal trapezohedral 622 \, D6 kalsilite and high quartz
ditrigonal bipyramidal \mathrm{\overline{6}2m} D3h benitoite
trigonal bipyramidal \overline{6} C3h none

See also

References

  • Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., pp. 78 - 89, ISBN 0-471-80580-7
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Hexagonal_crystal_system". A list of authors is available in Wikipedia.
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