relief carving

[Don Dougan <dondougan@xxxxxxxx>]

Anthony --

Re your question:  "on carving a relief into a slab of
green marble" You might try one of two things working
with hand tools:

1.  Put the workpiece in a bed of sand while you work on
it -- the sand will conform to all the various
directional stress trauma of the chisel blows.

2.  Imbed the slab in the upper surface of a block of
plaster  by casting the plaster around it.  My
estimation of the minimum thickness for the plaster
would be at least 5" plus the 1-1/2" of the slab itself.

The two solutions above will help to some extent, but
part of the problem is the nature of the stone itself.

Most 'green marble' is not a true calcium carbonate
marble at all, but serpentine.  For instance, the
Vermont Marble Company's green marble called VERDE
ANTIQUE or WINDHAM is serpentine, and it is harder than
the white Vermont marbles by a factor of 5 or more.
It's soundness rating (its structural soundness for
architectural purposes) is 'C' instead of 'A'  or 'B'.
'A' is what is usually preferred for sculptural
purposes, a 'C' rating translates into a tendency to
fracture along veining rather easily during carving.

Another option, since you are obviously willing to use
power tools as well as hand tools, would be to use a
regular -size die grinder with carbide burs of the
appropriate shape (just a bigger version of the Dremel
tool).  You can also use it with a 1-1/2" or 2"  diamond
wheel as well, or silicon carbide abrasive mounted
stones.   Wear a respirator. The cut of the tungsten
carbide bur, the diamond wheel, or the silicon carbide
abrasive wheels will be much less traumatic on the hard
brittle stone, but it will raise a good bit of dust (if
used dry) and be a fairly hefty investment in terms of
tools.

Good Luck

Don Dougan