  The two most common polymorphs in industrial alite, $M_1$ and $M_3$, were
characterized at the molecular scale. Different methods were employed and
discussed to assess mechanical properties and specific heat of both polymorphs.
The calculated homogenized elastic moduli and specific heat were found in good
agreement with experimental measurements. A comparative analysis of spacial
Young's modulus reveal isotropic and anisotropic spacial distribution for $M_1$
and $M_3$ respectively. A more isotropic compressive strength is also reported
for $M_1$ when compared to $M_3$ polymorph. Cleavage energies computation
allowed to proposed equilibrium shapes for both polymorph, with significant
differences. While the lowest cleavage energies were found along (100) and
(001) for both polymorphs, the constructed $M_1$ crystal possesses 3
independent facets, against seven for the $M_3$ polymorph.
