| water of hydration, formerly thought necessary to crystallization: now usually regarded as affecting crystallization only as it forms new molecular combinations. |

| water of crystallization n. Water in chemical combination with a crystal, necessary for the maintenance of crystalline properties but capable of being removed by sufficient heat. |
water of crystallization n.
Water in chemical combination with a crystal, necessary for the maintenance of crystalline properties but capable of being removed by sufficient heat.
| water of crystallization
Water in a crystal structure that is chemically combined with the other elements in the crystal. The water of crystallization is necessary for the maintenance of crystalline properties, but it can be removed by heat. |