Is it ivory -- or a plastic imitation? Learn how to find out ... safely.
by Dennis Gaffney
At the Omaha ANTIQUES ROADSHOW, Stuart Whitehurst, a senior appraiser at Skinner Inc. in Boston, described an age-old test that ivory lovers have used to distinguish their ivory from plastic pretenders. The test consists of heating up the point of a needle until it's red-hot and then pricking what you believe is your ivory carving. If the needle goes in, it's plastic; if not, it's probably ivory, or at least bone.
"If we were to do a hot-needle test on that," said Stuart, referring to a carved plastic pig in his conversation with ANTIQUES ROADSHOW host Lara Spencer, "that needle would go right into it and make him squeal."
That hot pin test has been around for as long as plastic has been made to look like ivory, but there's a problem with it: If the piece you're poking is a piece of vintage plastic jewelry, especially a name brand, you could be damaging your piece and ruining its value. "Really, any destructive test should be the last resort, if one at all, not the first," says Gloria Lieberman, director of fine jewelry at Skinner Boston.
Jeanenne Bell, owner of Jewelry Box Antiques in Kansas City, Missouri, agrees that it's best to use non-invasive tests. "You can often rely on the things God gave you to test your ivory," she says. "You can often figure out what you have by using your hands, your eyes, and even your teeth." The author of How to Be a Jewelry Detective says that one of the easiest ways to distinguish between ivory and plastic fakes is to pick them up. "Plastic is usually a lot lighter than the ivory," says Jeanenne, who notes that it does take some practice to get the feel for how much a piece should weigh. "If you go to antique shops or shows and you see something that looks like ivory, ask to see it and hold it. Ask if it's plastic or ivory. Don't be shy." Gloria has another trick that relies on the sense of touch: put the piece your cheek. Plastic will feel warmer than ivory.
The next piece of equipment that you should use to distinguish plastic from ivory is your eyes. Jeanenne recommends you look and feel for the seam that is often detectable in a piece of molded plastic. Stuart points out that ivory also has circular rings, not unlike the rings of a tree, that can be seen with the naked eye. Gloria suggests you use a magnification loop to inspect the differences in the surface structure of plastic and ivory. Plastic is non-descript upon magnification, but you can often see cross-hatches on the surface of a piece of ivory when it's magnified.
A test that Jeanenne has developed herself over the years is to tap a piece in question against the edge of her bottom row or teeth. "I can tell in two seconds what it is," Jeanenne says. "Plastic just sounds more plasticy."
The last God-given gift that the Kansas City jewelry expert recommends using is your mind. "If you see what looks like ivory on a piece of costume jewelry covered with rhinestones, well, then, it's probably plastic," Jeanenne says. "And if it's fine gold jewelry, it's probably ivory."
Two books that will help you figure out what your piece of jewelry is made out of are:
Jeanenne Bell, How to Be a Jewelry Detective, Antiques Detective Publications, 2001.
Jeanenne Bell, Answers to Questions About Old Jewelry, 1840-1950, Krause Publications, 2004.
posted on 03.23.05