planes in granite

["George Graham" <georgergraham@zzzzzzzzzzz>]

Norman,
I can't tell you why there is 3 planes in granite, but it is essential
for a stone cutter to know where the grain is and where it is going. All
the granite I used to work with came in slabs or quarry blocks. All the
slabs where cut across the grain so when I was pitching the stone to a
line, I was working with the grain. It's very much like splitting wood.
Easy to split with the grain, much harder to split when going across the
grain. Going across the grain of granite is easier then splitting wood
across the grain , which is impossible.

When dealing with quarry blocks, the quarry drill holes marks were
usually the best indicator of what the grain was doing. A line of short
holes on the side of a split face that was 3 feet tall is a good sign.
If the face is straigt and true, then I would work off of it. An old
quarry man told me that you would feel the different grains by running
you hand over the split surface. The workable grain had a distinctly
smooth feel to it, compared to a sharp, prickly feel going cross grain.
Of course when in doubt, I would take a strokes with a hammer and hand
set to get a feel for how it broke.

One the most interesting things about granite, the grain and its
workability, is that all granite pitches and splits differently.
Learning the different chacteristics was a matter of trial and error.

I didn't answer your question, but you touched on one of my favorite
topics. Over the summer we toured Yosemity. I don't care how many great
pictures one can look at, nothing compares with going there. The wall
paper on my computer is a picture of El Capitan rising 3000 feet up over
the trees on a perfect blue sky!

Got stone to carve now,
George Graham