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Hexagonal crystal system
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(Redirected from 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 |  |
D6h | beryl |
| dihexagonal pyramidal |  |
C6v | greenockite |
| hexagonal bipyramidal |  |
C6h | apatite |
| hexagonal pyramidal |  |
C6 | nepheline |
| hexagonal trapezohedral |  |
D6 | kalsilite and high quartz |
| ditrigonal bipyramidal |  |
D3h | benitoite |
| trigonal bipyramidal |  |
C3h | none |
- Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., pp. 78 - 89, ISBN 0-471-80580-7