The Crystallographic Teaching Collection was established by Prof. Wilhelm (Will) Kleber at Humboldt University of Berlin in the 1950s. The collection comprises about 1100 objects which can be assigned to 4 main categories: 1. minerals (approx. 500) exhibiting naturally grown crystals, 2. polyhedron models (approx. 500) made of cardboard or wood, 3. models of crystal structures (approx. 50), 4. didactic models (approx. 70). The benefit of the collection for teaching is that it enables the direct comparison of naturally grown crystals with their idealized form (polyhedron models) and their internal structure (structure models). In addition, didactic models strongly support crystallography and solid-state physics courses by visualizing teaching content which is challenging to understand when just verbally explained or visualized by two-dimensional viewgraphs.