Because of its alluring properties and relative scarcity, gold is more precious than silver. The same used to be true for ivory when compared to bone. Although it is easy to distinguish gold from silver, it is not necessarily the same with ivory and bone, yet the implications include legal ones.
Should you come across an irresistably beautiful crafted white object in an antique store, can you trust the dealer’s word regarding its composition? Museum curators and the US Fish and Wildlife Service also have vested interests in bone vs. ivory. How can you tell them apart?
Even from afar, consider the object’s size and shape. If it is curved, 3 feet long and tusk-shaped, it is ivory. Duh! If it is short, stout and conical, and scrimshawed by a 19th Century sailor, it is a whale’s tooth. If it is at least 3 inches square and flat, it is bone—panbone, which is a whale’s jawbone. Sometimes the panbone is 25 feet long; and at the end where it contacts the skull, the bone is thin and flat and can yield a piece as large as 7″ x 12″. No tusk can match these dimensions.
Then, disregarding size and shape, consider its context. If the object came from an 18th Century royal treasury and is encrusted with emeralds, it is likely ivory. If it is flat and fully painted with a scene or portrait, it is likely bone, since probably nobody would paint over precious ivory. That would be like wrapping a nice gold tray in aluminium foil. If the treasure was unearthed from a Native American mound in Illinois, far from elephant and marine mammal habitats, most likely it is bone, although it could conceivably be a prehistoric mammoth tusk.
On close examination, aided with a magnifying lens if necessary, ivory has a pattern of cross-hatched lines. These are known as Schreger’s lines, and they intersect at different angles in elephant and mammoth ivory. Bone does not have such lines, but its surface will usually have tiny, dark dots and dashes. In life, these were minuscule passageways that allowed blood vessels to nourish the bone.
Then there is the hot pin test. A pin point heated red hot and touched to an inconspicuous area on an ivory object will not affect it. On bone, the hot pin is said to produce an aroma of “burning hair.” This may be helpful if you know what burning hair smells like.
Perhaps it is better to have a professional, who does not have a vested interest in the answer, appraise the treasure. In the past, I can imagine that many bone objects were promoted to unsuspecting souls as ivory. With few and diminishing exceptions, there are stringent bans on the international sale of ivory; and in a growing number of states, including California, New Jersey, New York, Washington, and Hawaii, trade in ivory is banned altogether. So now an unscrupulous dealer might try to jettison his no-longer-marketable ivory objects by labeling them bone.
I wondered if that was the case when I saw a graceful backscratcher in an antique shop just across the river from the Louvre. The dealer said that it was old and made of bone and named a hefty price. It was finely crafted, quite smooth to the touch, and without any dark dots or dashes. Based on its size and shape, it could have been either bone or ivory. My uncertainty combined with a mental image of the US Fish and Wildlife Service marching me off to the slammer led me to leave it alone. I’ll have to find another gift. “Do you have anything in bone? You sure it’s bone?”
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