Most minerals have a distinctive color that can be used for identification. Different causes may explain the existence of all these colors. Most of the theories explaining their existence in minerals and crystals rely on chemistry and physics. In fact, the behavior of electrons in both atoms and ions ; as well as the interaction with light clearly explains the existence of this wide range of colors. It is worth noting that colors in most minerals and crystals come from the selective absorption of light according to different processes and from some optic effects.