Yes there are a number of man made replacements for Ivory. Micarta
(Tufnol is the industrial name) Westinghouse makes one version.
Rucarta is another that is another a very hard product there is
Coral rucarta, Linen rucarta It is handled by the AG Russel knife
company Lowell Arkansas.
Ivorine is an all plastic resin product
Ultra Ivory, Eagle Grips Company Carol stream Illinois
Corian counter top works just like wood or ivory.
You can pick up a cue ball, as they are made from materials that
duplicate the real thing.
Also most of the pen making sites, or wood working suppliers have a
faux ivory in square blocks and round stock, in sections. Again it
is as close to the real thing as possible next to the tagau
More properly called the ivory nut palm. Here is one place that has
the round blanks in assorted sizes
One important thing about working with bone, Do not breath in the
dust, when working with it. In addition to the bone dust you will
also be breathing in any residual chemicals used to bleach and
prepare the bones. You never know what is used when they are
imported from overseas. With human bone dust there are a number of
illnesses that can be transmitted by inhaling the bone dust.
If you would like some very good books on Ivory and its replacement
carving try here they seem to be the place for books on ivory and
scrimshawing. http://www.schifferbooks.com Either of Jim Stevens
books are great for working carvers. They also have a very good
supply list of the real stuff pre CITIES elephant, mammoth,antler,
bone and man made.