Anything marmoreal is smooth and white or otherwise characteristic of marble, like a pale face or a tombstone.
Marmoreal is an old-fashioned, fancy word for "marble-like." It describes anything that resembles marble in appearance or quality. This could be a statue with a polished, smooth surface or an elegant building with marble-like columns. You can use the adjective to describe people as well — especially if they're a bit pale or rigid in appearance.