Some cracker tins include a glass vial of drying material in the lid to keep the crackers crisp. In many cases, the material is a mixture of magnesium sulfate and cobalt chloride indicators. As the magnesium sulfate absorbs moisture (MgSO4 ∙ H2O + 6H2O MgSO4 ∙ 7H2O), the indicator changes color from blue to pink (CoCl2 ∙ 4H2O + 2H2O CoCl2 ∙ 6H2O). When this drying mixture becomes totally pink, it can be restored if it is heated in an oven. What two changes are caused by the heating?