Sometimes the things that are most interesting under extreme magnification are the most boring at regular size. Take chalk – it looks like an undifferentiated mass of whiteness, hard to the touch. But zoom in a few hundred times and a very different picture becomes clear. Chalk is actually composed of tiny white spheres that are the aggregation of the ancient skeletons of phytoplankton algae. Those skeletons are compacted together by water and time to create the substance we know from elementary school, but the spheres are clearly visible under a high-powered microscope.
Image credit: Wikimedia Commons