Marble resistance to Weather

[abknight@zzzzzz]

Thanks, Simon

It is interesting to know that calcite turns to gypsum
when exposed to sulphiric acid.

As I gather from Dr. Palmer's contribution hardness of
marble is largely a function  of it's crystal size.
Certainly the finely grained Carrara Ordinario is much
harder than our Vermont Danby, or Colorado Yule wich have
much much larger crystals.  Does the Ordinario, then, as I
have heard it said it does, have better weathering
resistence.  It would kind of seem like it would.

Is Staturario the same as Ordinario?  I have carved some
Ordinariio C and have a sample of Bianco P which suprised
me with its surgariness/softness.
The Italian marble is certainly the industry standard in
outdoor detailed carving.  Is that because the Italians
lead the industry of detailed outdoor placed carving or
because they have a more weather resistant stone.  The
condition of out door marble sculpture, say, in Rome does
seem better than in our local Cemeteries, where after 150
year a face may have no nose.  I haven't ascertained the
marble used.

Thanks,

Bill