Minerals form the building blocks of almost everything on Earth. They are made up of crystals—regular, repeating atomic structures that fit together like a three-dimensional pattern. When minerals deform, their normally ordered crystal lattices develop linear imperfections known as dislocations. These are small breaks or shifts in the atomic arrangement that allow crystals to change shape under stress. Some deformed crystals contain large numbers of dislocations, while in others they are sparse and searching for them is like looking for a needle in a haystack.
