If the gold nuggets consist of only a few to a few thousand atoms, the properties of the metal change continuously. The brilliant colours of Gothic church windows come from such nanoparticles of precious metals formed in the window glass. The observed colour depends on the size of the nanoparticles and the type of metal. In a very defined, regular arrangement, certain gold nanostructures guide the light around an object instead of reflecting it: The observer only sees what is behind the object, but not the object itself. However, if you wanted to make a Harry Potter-style cloak of invisibility out of this material, you would have to use very complex structures made of different, particularly small particles for the different wavelengths of light. So far, this has only been possible for small areas.

In basic research, gold nanostructures make it possible to observe individual molecules or to switch individual molecules with light for future applications in optoelectronics. As a catalyst, gold helps to minimise the energy input of chemical processes at moderate temperatures and even to use sunlight as an energy source. There are several scientists in Oldenburg who are working on this fascinating element. It was not without good reason that Gretchen said in Faust, the first part of Goethe's tragedy: 'Everything depends on gold. Oh poor us'."