Based on diffraction analysis of amorphous Ge, pentagonal structure elements have been proposed. In a search for evidence other than diffraction from amorphous films for such structure elements, small (100 Å) particles of Ge were evaporated onto cleaved NaCl under almost epitaxial conditions and examined by electron microscopy and diffraction. These particles contain numerous primary and secondary twins. Each (100) oriented nucleus can, in principle, give rise to four primary and 12 secondary twins; however, only four of the possible 12 secondary twin orientations are observed. With crystallographic structure models one can extrapolate the boundaries between the observed twin orientations to a common line of intersection where indeed regions with pentagonal stacking sequence occur. Based on this result, a model for an idealized structural unit in amorphous Ge is proposed.