bipyramid

[bahy-pir-uh-mid]

noun

Crystallography.

1. a form symmetrical about a plane dividing it into two pyramids.

bipyramid

/ ˌbaɪˈpɪrəmɪd /

noun

1. a geometrical form consisting of two pyramids with a common polygonal base

Other Word Forms

• bipyramidal adjective

Word History and Origins

Origin of bipyramid¹

bi- ¹ + pyramid

Example Sentences

Tetragonal bipyramid of the second order.

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It may be considered as the hemihedral form of the ditetragonal bipyramid.

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The general form is bounded by twelve scalene triangles and is a ditrigonal bipyramid.

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The hexagonal bipyramid so common in quartz is geometrically similar to this form, but it really is a combination of two rhombohedra, a direct and an inverse, the faces of which differ in surface characters and often also in size.

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