_If_ some of its properties change depending on the direction you measure, it can’t look the same in all directions. As a simple example, consider graphite. Th

_If_ some of its properties change depending on the direction you measure, it can’t look the same in all directions. As a simple example, consider graphite. That’s just ‘C’, but the crystalline version is layered, so it behaves differently depending on what direction you look at it. Like wood, it will split easier when hammered parallel to the layers than when hit oblique to it.