and Mammoth Ivory
Most of us love elephants and hate the very idea of killing them for
their tusks and hate even more the poachers of today. However, for most
of history, ivory has been a favourite medium of artists and artisans.
Many of the finest chess sets have been made in ivory. All of the ivory
sets illustrated on this site are more than 100 years old.
Trade in ivory is regulated by CITES - the Convention on
International Trade in Endangered Species
. The only elephant ivory
that can be legally sold is that
that has been worked, that is carved, before 1947. All trade in
unworked ivory is banned. You can buy and sell pre-1947 ("pre-ban")
ivory within a country. Export across borders requires a CITES
Fortunately, there are huge quantitities of tens of
thousands of year old mammoth ivory that can be legally sold. We can
distinguish between mammoth and elephant ivory from their patterns of Schreger lines
. The Schreger are
the cross-hatched lines that are best seen in ivory cut at 90 degrees
to the length of the tusk. A scientific paper on the angle of
intersection of the lines found that the 90 degree-cut mammoth lines
generally cross at an angle of less than 90 deg whereas elephant ivory
at generally more than 115 deg.
from THE HISTORY AND SIGNIFICANCE OF THE SCHREGER PATTERN IN
PROBOSCIDEAN IVORY CHARACTERIZATION
EDGARD O'NIEL ESPINOZA, & MARY-JACQUE MANN
JAIC 1993, Volume 32, Number 3, Article 3 (pp. 241 to 248)
Below is a photo of the base of an 1850
Jaques king, with rather
diffuse Schreger lines crossing at an obtuse angle (Left), and the base of a modern
king made from mammoth ivory, with sharp Schreger lines crossing at a
more acute angle (Right).