Expert: Dmitry Livshits - 2/18/2011

Question
QUESTION: I am interested in buying a "Key Date" Chinese Panda Coin. I know how extensive the Fakes are of this particular year of coin and because of that,I have asked the seller to do a few checks on the coin for me. We are getting on very well and he has been very helpful,but we have a real problem. The Physical checks on the coin, Diameter,thickness,weight and ALL visual checks are exactly as they should be for that year of coin. However the specific Gravity reading for the coin has shown on test to be 9 first time and 9.3 when checked again. As the specific gravity of silver is 10.5, this is way off and implies the coin is NOT silver. However, how can ALL the physical dimensions be correct for the coin, including the weight, if it was NOT silver. Surely a coin of the same dimensions, made of something other than pure 999 silver; would not weigh the same as the real coin would weigh. If it is a Fake, then it is the most perfectly detailed one I have ever seen and I have every silver Panda Coin minted, in my collection.
With Kind Regards

ANSWER: Hi Martin,
I think it's most likely that the specific gravity meter is off, especially considering the subsequent readings of 9.0 and then 9.3. This is beyond the margin of error for any good meter.
Also the diameter, thickness and weight of a coin made from a less dense metal cannot possibly be identical to a coin made of a more dense metal. Physics simply will not allow it.
Thanks for the question! =)

---------- FOLLOW-UP ----------

QUESTION: Thanks for the reply,I should have explained that the "Specific Gravity" test was not carried out with a meter; but physically,by suspending the coin in water on scales and doing the mathematics. Under THOSE circumstances,a discrepancy of 0.3 is not too unreasonable. As far as producing a coin of definitive physical dimensions, which weighs the same as a pure 999 Silver coin; I suppose this could be achieved by using a combination of more dense (heavier) and less dense (lighter)materials in the right quantities.I am reliably informed by the Panda Collector Website,that long discussions have been going on about this particular FAKE and how to recognize it. The "Specific Gravity" test however,although perhaps not perfectly accurate,is definitive in exposing this particular coin as a FAKE. They estimate that for every one 1oz Silver Mirror Panda Coin from the year 2000 that is Genuine, there are 20 FAKES on the market.
Many thanks for your reply,it is much appreciated.
With Kind Regards

Answer
Hi again Martin,
This is something entirely different from typical fakes. The quest to make metal alloys with similar properties to precious metals is as old as the term "alchemy" itself.
In order to achieve this a huge effort would need to be undertaken. Knowing what I do about how China operates, I would not be surprised if this was one example of a ring of "state sponsored" counterfeit coins.
Thanks again! =)