Everyday things have interesting aspects if we choose to explore them a little. Crystallography studies substances in the solid state. When a chicken egg is considered, only the shell is solid. That's what we decided to analyse using X-ray diffraction.
The shell is approximately 0.3 mm thin and consists of several layers. Beneath a thin upper layer, which is responsible for the colour of the egg, there is a layer of calcium carbonate crystals which are bound together by an 'organic glue'. A simple diffraction experiment shows that calcium carbonate occurs here exclusively in the form of calcite. At Easter, however, we can also see chocolate eggs. Their 'shell’ composition is completely different. If we shine an X-ray on this egg, we can see sugar crystals and crystalline cocoa butter. Yes, even something called butter is internally ordered, i.e. crystalline. Whether natural or chocolate, the egg shows that even the ordinary objects around us hide extremely interesting things beneath the surface. You just have to look at them the right way.