de marbre

stone-faced; unmoved

→ de
phrase Rare #52,473
stone-faced; unmoved Used figuratively to describe someone who shows no emotion or reaction.
FR: Elle est restée de marbre devant la nouvelle.
EN: She remained unmoved by the news.

Et tu restes de marbre ?

And you’re still unmoved?

— Mystic River (2003)

Alors, visage de marbre.

Well, keep a straight face.

— Des hommes d'honneur (1992)

Avec sa tête de marbre, il fait ainsi.

With his marble head, he does so.