I have an antique chess set that I believe is made of ivory.  I plan
on selling it, but I want to ensure that it IS ivory before I sell it
as such.  I am concerned that it may be bone.  Are there guidelines
for determing which one it is?  Is there a way to do this without
damaging any of the pieces?

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Request for Question Clarification by pinkfreud-ga on 06 Jan 2003 20:12 PST

I have found several useful articles that discuss how to tell bone
from ivory.

None of these are specifically oriented toward chess pieces, however.

Will you accept an answer that provides links to discussions regarding
methods of distinguishing bone from ivory, but that is focused on
other kinds of artifacts?

Hi val48~

In addition to wondering whether your set is ivory or bone, you will
also want to consider the idea that the set may be celluloid or some
other early form of plastic.

SYNTHETIC OR NATURAL?
To first determine if the set is natural or celluloid, feel the pieces
carefully. Are they smooth, or irregular? Is the item at all
transluscent? Are there carving marks? Does it feel warm or cool to
the touch? When you tap a piece with a fingernail, what does it sound
like? If celluloid, it will feel smoother, will not have carving
marks, and will feel cooler than ivory or bone. Celluloid (an early
form of plastic) will sound much different than bone or ivory, and can
be transluscent. (Bone will *not* be transluscent at all, although
ivory can be).

Hold one of the pieces in your hand for a few moments to warm it. Does
it emit a natural or synthetic smell? If you are familiar with early
plastics, you will recognize the scent of them right away.

If there are any designs on the pieces, look for irregularities. If
each design looks exactly the same, it is not ivory or bone, which
would need to be decorated by hand.


IVORY OR BONE?
To tell if a piece is ivory or bone, you'll need a jeweler's loop (or
other good magnifier). Carefully examine all the pieces you think may
be ivory, looking for what is called the "Haversian system" (which is
what remains of the vascular system in natural bone). It will look
like streaks, or little pores (often darkened over time). Ivory will
*not* have any traces such as these, so if you find evidence of the
Haversian system, the item is assuradly bone. Be sure you study *all*
the pieces, as it's possible for the Haversian system to show up on
some bone pieces, but not on others.

If you do not find any trace of the Haversian system, hold the pieces
up to a strong light. Usually, with ivory you can see a cross-hatch,
chevron-looking, or wavy pattern. When you see one of these wavy
patterns, turn the piece 90 degrees. If you can *not* see the pattern
any longer, the piece is ivory. These patterns are often described as
pearescent.


For a helpful guide to possible materials, you might also check out:
http://www.sloperama.com/majexchange/id.html

Good luck, and hope this helps!

Kriswrite

Keywords Used:
ivory vs. bone
://www.google.com/search?q=ivory+vs.+bone&hl=en&lr=&ie=UTF-8&start=10&sa=N

Identify ivory bone
://www.google.com/search?hl=en&lr=&ie=ISO-8859-1&q=identify+ivory+bone