Carved Flowers in Fireplace Panel. Paint Stripped
For marble “health” the marble have to “breath”, otherwise it will accumulate a moist, what may lead to decay, staining and changing the chemical composition of a marble.
The “breath” mean the marble should not be coated, painted or crystallized. A marble have to have a contact with dry air most the time.
On the picture below you can see the brownish stains due to keeping marble under paint throughout many decades.