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.

From Project Gutenberg

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

From Project Gutenberg

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

From Project Gutenberg

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.

From Project Gutenberg