# rhombohedron

## Definitions

• WordNet 3.6
• n rhombohedron a parallelepiped bounded by six similar faces (either rhombuses or parallelograms)
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Webster's Revised Unabridged Dictionary
• n Rhombohedron (Geom. & Crystallog) A solid contained by six rhomboids; a parallelopiped.
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Century Dictionary and Cyclopedia
• n rhombohedron In geometry and crystallography, a solid bounded by six rhombic planes. In crystallography a rhombohedron is usually regarded as a hemihedral form of the double hexagonal pyramid. It may be obtuse or acute, according as the terminal angle—that is, the angle over one of the edges which meet in the vertex—is greater or less than 90°.
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Chambers's Twentieth Century Dictionary
• n Rhombohedron rom-bō-hē′dron a solid bounded by six rhombic planes
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## Etymology

Webster's Revised Unabridged Dictionary
NL., fr. Gr. rhomb + seat, base
Chambers's Twentieth Century Dictionary
Gr. rhombos, rhomb, hedra, a base.

## Usage

### In literature:

As in the other rhombohedral carbonates, the crystals possess perfect cleavages parallel to the faces of the rhombohedron.
"Encyclopaedia Britannica, 11th Edition, Volume 4, Part 4" by Various
Thus in calcite the rhombohedral angle (the angle between two faces of the fundamental rhombohedron) is 74 deg.
"Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7" by Various
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### In science:

This tiling consists of two different elementary cells, the “oblate” and “prolate” rhombohedron.
Random tiling quasicrystals in three dimensions
In the addition method the probabilities for adding a certain rhombohedron at a certain place have not been taken into account.
Random tiling quasicrystals in three dimensions
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