didodecahedron

plural didodecahedra · plural didodecahedrons

1. geometryA solid with 24 faces consisting of scalene triangles.

   […]a pair of opposite edges of every face are parallel, so that the form shows prominent zonal relationships which are not characteristic of didodecahedra in general.

   1946, F[rank] C[oles] Phillips, “The Thirty-two Classes”, in An Introduction to Crystallography, Longmans, Green and Co., part I (The External Symmetry of Crystals), pages 145–146

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   Didodecahedrons are never seen in crystals, as predominating forms; but they are frequently met with as modifying faces, in combinations, principally in those in which the 6-sided prism predominates.

   1853, “Crystallography”, in Th[omas] Forrest Betton, transl., edited by James C[urtis] Booth and William L. Faber, Elements of Chemistry. For the Use of Colleges, Academies, and Schools., 2nd edition, volume I, Philadelphia, Pa.: Clark & Hesser, translation of original by [Henri] V[ictor] Regnault, section “The six systems of crystalline forms”, subsection 3 (Hexagonal system), page 34