Broken egg shell, coloured scanning electron micrograph (SEM). This is the edge of a piece of a chicken's egg shell, viewed from the inside and showing the two inner membrane layers. The eggshell membranes are thought to give strength to the eggshell and make it less brittle. They are also important to guiding the crystallisation of the calcium carbonate component of the shell. Magnification: x885 when printed at 10 centimetres across.