Crystal growing in an aluminium alloy sample. Close-up of an atom probe tomography (APT) image showing a new crystal forming in an aluminium alloy. Atoms are represented by dots and are colour-coded. The concentration of zinc (dark blue) and magnesium (green) atoms has become high enough in the red zone to distort and change the orientation of the ordered planes of aluminium atoms (turquoise) by about 6-7 degrees, forming a new crystal within the metal. The background colour gradient indicates the increasing concentration of the zinc and magnesium atoms. The rows of atoms are approximately 0.2 nanometres apart.