<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Crystals of MgCl<sub>2</sub>·8H<sub>2</sub>O (I), MgCl<sub>2</sub>·12H<sub>2</sub>O (II), MgBr<sub>2</sub>·6H<sub>2</sub>O (III), MgBr<sub>2</sub>·9H<sub>2</sub>O (IV), MgI<sub>2</sub>·8H<sub>2</sub>O (V), and MgI<sub>2</sub>·9H<sub>2</sub>O (VI) are grown from their aqueous solutions at below 298 K according to their solid‐liquid phase diagrams.</p> </abstract>