Publisher Summary This chapter discusses hydrothermal synthesis and growth of coordinated complex crystals like silicates, germanates, phosphates, vanadates, and borates. There is a close relationship between crystal chemistry and crystal growth of these compounds. The primary requirement for any material/crystal/mineral with a device potential is the understanding of its scientific foundation, particularly the consequences of the submicroscopic crystal structure, i.e., the spatial arrangement of atoms, ions, molecules, and the types of chemical bonds between them. It is the chemical bond more than anything else that determines the structure and the properties of a crystal. A crystal chemical knowledge helps in tailoring a given phase or a given structure that is to optimize chemical classification, crystal structure, and defect structure with respect to the desired properties.