Reversablity of dehydration
Yes, in fact this process is similar to the processes in lime stone that form cave stalagmite and stalactites but with calcium carbonates.
$$\ce{M(HCO3)2 &lt;-&gt; MCO3 + H2O + CO2 }$$
$$\ce{M} = (\ce{Mg},\ce{Ca})$$
Though I should note the process in not called dehydration.