Strontium Hydroxide occurs as an anhydrate whose prismatic, colorless
crystals are deliquescent. A monohydrate and octahydrate
are also known.Strontium hydroxide is slightly soluble in water but,
surprisingly, the octahydrate is much more soluble. It
is the latter that is supplied commercially for most applications.When the octahydrate is heated, seven waters of
hydration are lost to form the monohydrate and finally the oxide.