Crystal growth technology involves processes for the production of crystals essential for microelectronics, communication technologies, lasers and energy producing and energy saving technology. A deliberately added impurity is called an additive and in different industries these affect the process of crystal growth. Thus, understanding of interactions between additives and the crystallizing phases is important in different processes found in the lab, nature and in various industries. This book presents a generalized description of the mechanisms of action of additives during nucleation, growth and aggregation of crystals during crystallization and has received endorsement from the President of the International Organization for Crystal Growth. It is the first text devoted to the role of additives in different crystallization processes encountered in the lab, nature and in industries as diverse as pharmaceuticals, food and biofuels. A unique highlight of the book are chapters on the effect of additives on crystal growth processes, since the phenomena discussed is an issue of debate between researchers