18-6 gyrochoron

The 18-6 gyrochoron, also known as the trigon hexacoil, is a convex isochoric polychoron and member of the gyrochoron family with 18 tetragonal antiwedges as cells.

Each cell of this polychoron has mirror symmetry, with 2 tetragons and 4 triangles for faces.

Isogonal derivatives
Substitution by vertices of these following elements will produce these convex isogonal polychora:
 * Tetragonal antiwedge (18): 18-6 step prism
 * Kite (18): 18-6 step prism
 * Isosceles triangle (18): 18-6 step prism
 * Edge (18): 18-6 step prism
 * Edge (36): 36-6 step prism
 * Vertex (18): 18-6 step prism