jc,

Is this one of those, "I was floating down the Missouri River on a
steamboat toward dusk with a full house in my hand and noticed out the
portal what looked like stone on the eyebrows of a masonry Bank along
the muddy bank, but I was not sure if it were not precast.", questions?

I'm reminded of one time my being absolutely stumped when I told an
architect that what he was specifing as concrete repair was actually to
be applied to limestone and he asked me how I could tell the difference.
We were standing right there looking at it. I particulary noticed that
he did not touch the stone. I think that I was polite in my response but
I also note that I don't do business with that outfit and don't want to.
It was one thing to be ignorant of something that to me seemed so
obvious, it was more of a problem when I figured out that they were
ignorant all over the place.

The complex answer is that if you have had your hands on real stone all
your life that fabricated stone not only stands out as very obvious, in
some cases it causes nausea -- this is a complex reaction and the 'barf'
index to me is the most readily observable difference. I stopped in a
brickyard earlier today, I happened to be driving along with a few
minutes to spare, and it was full up with colored concrete pavers. The
stuff makes me feel ill to be around it. Whereas... we have ultra-cheap
concrete pavers in a portion of our yard with about 30 years of buttina
and related detritus and I don't feel all too bad about making a hell of
a mess on them. I will admit though that I absolutely love the 50's era
molded concrete block.

One thing that you may notice with 1930's cast stone is that the design
mixes were not as standardized as contemporary manufacturing tolerances.
It should be fairly easy to tell the difference between 1930's cast
stone and natural stone. You might tap it with your pocket knife and see
how it sounds. Where the cast stone is deteriorated and turned to shit
it is a no-brainer to notice the difference -- even from the leisure of
a steamboat. Where it has survived in fairly good condition it may be
more difficult to figure out but if the exposed aggregate looks like
pebbles or small chunks and not like crustacean shells, and is
consistent throughout and not in swirls, waves or bands then it is
likely a candidate for precast.

][<

>The simple answer is yes.
>
>
>>Are there any readily observable differences between good 1930's cast
>>stone and natural stone?
>>

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