Geometric or crystalographic, complete or schematized figures that, integrated in a single piece, are simultaneously visible. (Machine-translation by Google Translate, not legally binding)

摘要

Geometric or crystallographic figures, complete or schematized that, integrated in a single piece are simultaneously visible, characterized by the fact that, thanks to the total or partial diaphaneity of their faces, their dimensions are appreciable to notations that are related to each other, mathematics or crystallographically, either by triangles or connection polygons, either by the position of the holohedral forms with respect to the hemihedral ones that they engender or by the position with respect to the axial cross. (Machine-translation by Google Translate, not legally binding)