Re: Can limestone be used to protect marble.

Justin, you're thinking along the right track. Lime (CaO), a product of 
limestone (CaCO3), is added not to marble but to acidified lakes because 
it reacts with acid to produce CO2 in a reaction similar to the one you 
mentioned:

CaO + H2SO4 -->CaSO4 + H2O 

But marble is just a special limestone, a harder variety that allows it to 
be polished. So if you coated marble with run of the mill limestone, you’d 
be eliminating the properties that make marble special.

The way to protect marble from acid rain is to stop it at the source. 
There are scrubbers that can absorb sulfur emissions ( which go on to form 
one of the acids in acid rain) and there is public transportation which 
reduces the number of vehicles on the road and hence the nitrogen dioxide 
emissions which lead to another component of acid rain.

Enrico