Has Mexico 1980 Onza Been Counterfeited?

The 1980 Onza's were sterling ( .925 ) silver. Starting in 1982 they were made from .999 silver. I have read different things about counterfeit Libertads. One said that the counterfeit 1982's were made from .925 but marked as .999 ley Plata Pura.

I also read that some counterfeit Libertads were made from iron with a silver plating and that they were mildly magnetic.

I read on another forum, a poster from Guadalajara had said that silver has always been so plentiful in Mexico, that when the poorer people were able to put money away, did so with silver coins, because no one trusted banks there. Now that silver has risen so much since 1980 people are turning in their silver for cash. Unfortunately he states, many banks in poorer parts of the country are taking advantage of this and paying out substantially lower cash than the spot price of silver. These ( hoards ? ) of uncirculated older silver being turned in , is now making it's way to the coin market.

The earlier 1979 & 1980 sterling onzas were heavily counterfeited so I'm in no doubt 1982 was too. Infact I have a fake and a real one myself...

The short answer is YES of course they have been counterfeited.

The comment about real silver coins emerging after being hoarded is also correct but the forgers are also at work. You need to know the seller or you are gambling.

The 999 fine bullion coins are not the same color as sterling silver. This means the counterfeits can be made with an electro-plate coating with no obvious color change. So the ore can literally be anything. I use Specific Gravity and a silver-copper alloy graph to determine the alloy. If SG is not near 10.5 you are dealing with a FAKE. The deviation from 10.5 determines actual value.

If the SG is under 10.3 or over 10.7, cut the coin open if possible with a knife. That will be the mark of a bad fake.

I usually pay 20% under spot to cover discounts when you bring them in for reclamation. They should be destroyed as discovered.

There is NO chart of silver contents for forgeries because the forgers change alloys - without telling anyone. In 1845 John Riddell produced a book on counterfeit Dollars that included a value that was set for each fake. That was a big mistake that got his work discredited from the get-go. He should have printed the pictures with NO CLAIM about alloy because counterfeiters use a lot of different metals.

Rely ONLY on tests done at point of sale and only use acid tests if the coin is cut in two. Surface readings are worthless except in the case of very old counterfeits.

OK Hands off these Onzas from now on. Sticking with US 90% to stack. Thanks!

However. I just received a shiney 1980 from the ebay seller who slabs all his coins. States it is MS-66. My powerful magnet does not attach - but will a magnet work through plastic? Should I unslab it?

My 2008 coin book states for the 1980 KM # M49b.5 that the "left scale pan points between you & N of UNA" However, the picture they provide for the 1980 has the scale pointing directly at the you - as does mine.

OK found the book on the Internet. Is 2004 the latest edition?

Where will I find your information here on forgeries? Especially silver coins.

Thanks so much!

"but will a magnet work through plastic?"

Depends upon "lift-off" (how much distance is between the magnetic source and the object), the Gauss rating of the magnet (how strong it is) and the ferromagnetic properties (permeability - how easily the object is magnetized) of the "coin".

Thanks I had thought of taking it out of the slab.