Simplicial bipyramid

The n-dimensional simplicial bipyramid is a Blind polytope formed by blending two n-simplices, or taking the convex hull of an (n - 1)-simplex with two additional points. Its facets comprise 2n (n - 1)-simplices. This family of polytopes generalizes the triangular bipyramid, a Johnson solid. The four-dimensional simplicial bipyramid is the tetrahedral pyramid, and the five-dimensional one is the pentachoric bipyramid.

In five dimensions and above, the simplicial pyramids and the orthoplecial pyramids are the only non-uniform Blind polytopes.