How old is that ivory?
There are two things law enforcement and the scientific community want to know about recovered ivory--where did it come from, and when? Relatively expensive DNA testing can determine the where part pretty accurately, but accurately assessing the age of an ivory artifact is becoming more and more important as legislation in destination countries becomes more restrictive. Potentially illegal carvings would be anything made from ivory that originated from material that came onto the market after the ban; any objects made from ivory that dates from prior to the ban is currently legal to deal in.
When the recovery of illicit ivory is on a grand scale, such as the September, 2011 seizure in Malaysia that netted more than two tons of elephant tusks, both carbon dating and the more expensive genetic testing can be used together to establish both the where and when the elephants were killed. That makes arresting the traffickers easier and gives the authorities a much better chance of eventually tracking down the poachers themselves.
While it can be argued that dealing in such legal, worked ivory does not contribute to the endangerment of the African elephant, it can also be argued that there is a need to prove that these pieces are indeed what they purport to be. The oldest trick in the book for dealers in illicit African ivory is to buy a small amount of registered ivory from the relevant regulatory body--the National Parks and Wildlife Management Authority in Zimbabwe--and then produce carvings and artifacts using illegally-obtained "back door" tusks. In this way, the legal ivory will "last" almost forever.
Genuine ivory is hard and compact, with lustre and resilience. Certain fractions, such as inorganic phosphates, cannot be accurately aged. However there are also organic--carbon-based--substances present which change with the passage of time.
Spectrometry testing is used in both qualitative determining whether or not a particular substance is in fact present--and quantitative--telling us how much of it is present --analysis. I read an interesting article a couple of years ago wherein it was postulated that because an elephant's tusk absorbs radioactive carbon deposited in the air by cold war nuclear tests, researchers could test a sample of recovered ivory to determine when the elephant was killed--the premise is that with the passing of each year, the amount of radiocarbon in the atmosphere declines slightly, with trace amounts being absorbed by an elephant's tusk.
This method makes use of the so-called "bomb curve", which is a graph--shaped roughly like an inverted "V"--showing changes in carbon-14 levels in the atmosphere. Atmospheric carbon-14 is absorbed by plants in the process of photosynthesis and subsequently incorporated into the food chain, being passed along to herbivores who feed on the plants. Radioactive carbon-14 was deposited into the atmosphere by American and Soviet atmospheric nuclear weapons tests between 1952 and 1962. Those levels peaked in the 1960s and have declined ever since but still are absorbed by and measurable in plant and animal tissues.
The University of Georgia's Center for Applied Isotope Studies in the United States has recently validated a technique for determining the age of an ivory artifact. Developed by Dr Adolf Shvedchikov, the technique is relatively inexpensive and does no appreciable damage to the specimen. In a recent test, according to Godfrey Harris, Managing Director of the Ivory Education Institute:
"The Ivory Education Institute sent the Center samples of two different objects Dr Shvedchikov had tested with his absorption/de-absorption technique: (1) A small plate of ivory he had rated as "young" elephant ivory--in the 25 to 50 year range; and (2) a fish-shaped gambling token found in an ivory-inlaid Persian box that had tested as "old." Shvedchikov's standard for "old" elephant ivory is anything more than 100 years old. Dr Alexander Cherkinsky, Director of the Center, reported on the 26th of May that "the most likely range for the [age of the] plate is between February 1972 and December 1973 and for the old fish between 1728-1804". The material used in the plate turns out to be just over 40 years old and the ivory used to shape the fish probably came to an Indian workshop more than 250 years ago.
Dr Shvedchikov was very pleased that the median of his estimate of the age of the "young" elephant ivory, based on his experiments, was within 12% of the laboratory's finding and his estimate of the "old" elephant ivory, using the same carefully calibrated methods, was well beyond the US 100 a year standard for an "antique". "We are greatly encouraged by these initial results and can now refine his methodology to lower the age range toward the same 3% to 5% zone that carbon dating experiences in its estimates. Our plan is to submit a second set of quite different samples to the University of Georgia Center by the end of June".
Oh, and just for the hell of it, how do you "artificially weather" ivory? It seems that the old timers used Condy's crystals--I love going through the late 19th century and early 20th century gunsmithing formula books just for the names alone! Which was back in die day-speak for potassium permanganate. Now, any pharmacy should have this in stock, but Big Brother is never far away, is he? In the States anyway, in its infinite wisdom, the US Food and Drug Administration has declared that"(1) Potassium permanganate and potassium permanganate tablets intended for human use are drugs subject to section 503(b)(1) of the Federal Food, Drug, and Cosmetic Act and should be restricted to prescription sale. Such drugs will be regarded as misbranded if at any time prior to dispensing the label fails to bear the statement Rx only.'" So there, take that!
Fortunately, without leaving the comfort of your home, you can just boil the skins of a number of onions into a sort of emulsion (which, according to ye olde lore, can also be used to dye wool, help cure leg cramps, dye hair, and colour Easter eggs), add a teaspoon or so of white vinegar and soak your ivory in that. It will mature nicely!.",
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|Title Annotation:||Around the Campfire: Sharing ideas, views and facts.|
|Publication:||African Hunter Magazine|
|Date:||Jun 1, 2016|
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