These crystals are certainly odd. I have for many years wondered at their layered cake appearance, and today just found it so funny that i had to make a spoof about it. So here are a few images taken from within a single hepatocyte phagocytic cell (like a resident macrophage) and these layered cakes ‘so to speak’ are oriented with the largest layer at the base and stacked vertically. The crystals appear to be stacked round layers, but probably not always, maybe with a chance orientation of smaller layers “up one”, I have not done any counting to see whether they might be “reducing in size as they stack”. The rounded bottom layer (not shown in these images) is seen in cross section sometimes as a full circle, other times as a tangential cut with one straighter edge and one rounded edge, just as one would find in a tangential cut of a layer cake.

At any rate, these are clues about the structure of perfluorodecyl iodide crystals in vivo.