Why does hot steam produce MgO instead of Mg(OH)2? Background research


Magnesium hydroxide exists naturally as brucite (source: wiki)
Passing hot steam over magnesium produces magnesium oxide (source: Edexcel's June 2014 Unit 2 exam (CH02_01): question 18)


Question

Why doesn't magnesium hydroxide form when treated with hot steam, instead of magnesium oxide?
There are two steps in the process:

$\ce{Mg + H2O -&gt; MgO + H2}$

and

$\ce{MgO + H2O &lt;-&gt; Mg(OH)2}$

The equilibrium point in the second step is dependent on the temperature. See file Equilibrium Assemblages for more information.