TESTING FOR IVORY
I repeatedly hear people either tell me or ask me about the so-called "hot needle test." THERE IS NO SUCH THING.
For generations the idea has persisted that if you touch a piece of ivory with a red-hot needle, it will not burn, but will char and smell like burning hair. This is supposed to confirm that the object is ivory. It is destructive. You need to ask two questions.
1. Would any intelligent person allow you to burn their ivory as a consideration for selling it?
2. Would you want a piece of ivory you own to have a burn mark on it?
There is no single test that will confirm that an object is ivory and ALSO reveal the type of ivory. There are ways, however, to identify ivory.
The first is to learn the gross morphology of the various raw tusks and teeth--that is, to understand the sizes, curvatures, grain patterns, and interior structures of them in their natural states. A person who knows what cross-hatching looks like is better prepared to make a determination that he is holding either elephant or mammoth. If they also understand the difference in the angles of the Schreger lines, they can further identify specifically which type it is. A person who knows what the secondary dentine of a walrus tusk looks like can easily identify an object as being made of walrus ivory.
Can you answer questions such as whether a boar tooth is triangular or rectangle in shape? Do you know whether the nerve root in an elephant tusk goes all the way to the tip? Do you know what a whale tooth or narwhal tusk looks like inside? If you do, you have a leg up in making a proper identification.
Comparanda is the concept of having learned all of the diagnostic characteristics and having built up in your memory a database of experiences. The more you handle the more you will learn and know. Don't pass up the opportunity to hold and examine every possible piece of ivory.
The hot needle test is not only a failure because of the damage it can cause, but also because many other substances such as bone, antler, and vegetable ivory will react exactly the same. And, celluloid, an early ivory substitute, is so flammable that a hot needle can cause a fire or even an explosion.
A black light (long wave UV) light, if properly used, can help separate out plastics. In general, ivory reflects the full spectrum and appears a bright blue when viewed in a totally dark area. Plastic on the other hand absorbs part of the spectrum and appears a dull blue or some off-color. While useful in separating out plastics, it doesn't prove that the bright blue object is ivory, for other substances can also appear bright blue.
You will learn to identify ivory by reading books that show pictures of the characteristics you should be looking for; by seeking assistance from a knowledgeable mentor; and by practicing yourself. There are also comparison kits available.
Finally, you can improve your chances of buying a properly described carving by dealing with knowledgeable sellers. Don't be afraid to ask a dealer to show you why a piece is ivory and for his reasoning for identifying the type. On the other hand, you must realize that sometimes heavily carved or painted small objects can be almost impossible to evaluate no matter how skillful the person selling it.
It pays to be an informed buyer.
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