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 Replies: 8 / Views: 7,440 |
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New Member
United States
24 Posts |
Hi. I have some 1 oz silver bars from Sunshine Mint that are packaged in the secure plastic. They look the same as those pictured on Sunshine Mint website. I came across an auction on ebay (Item 251003019131) for silver plated bars, but the picture posted looks the same as my bars. Would appreciate any help from anyone willing to help educate me on this. Thanks. |
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Valued Member
United States
362 Posts |
Well depending on the metal. A magnet test may work. If it attracts to a magnet then it is probably plated... And if it doesn't then it probably is silver (Although there are other metals it could be I think)
You should also weigh the bar. If it is the appropriate size (dimensions should match up perfectly to sunshine mints bars) and it weighs 1 troy ounce or whatever it says, then you are probably good.
There are other tests too... specific gravity tests, or you could even file away some of the metal and make sure its all the same material... although I would never do that unless I absolutely had to.
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Valued Member
United States
318 Posts |
Get a good scale and a set of plastic calipers. Weigh and measure and make sure that it matches what it's supposed to. Obviously you can't do this over the internet, that only works if you have it in hand. Buy from someone with lots of good feedback. You have to trust them, although ebay will be on the buyer's side in a dispute if you get cheated. |
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New Member
 United States
24 Posts |
A magnet doesn't seem to be attracted to them. As far as weighing them, they are encased in sheets of plastic so that may prove difficult. Thanks for the advice.
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Valued Member
United States
62 Posts |
Yes, the magnet test comes to mind and of course weight and dimensions. Obviously you can't do any tests for online purchases until you receive the bar (in which case you've already bought it) which is why if I have any suspicion at all of the seller's integrity I don't purchase. If they have a lot of good feedback then you're probably fine...unless they're selling really good fakes that fool everyone!  |
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Bedrock of the Community
Australia
21786 Posts |
An alloy of copper tin and lead could be conjoured up to give the same density as silver, which is 10.5 grammes / cc. Over that a thick silver plating can be applied, then the bar stamped as genuine.
That brings you down to a detailed examination of the stamping detail of a die stamped fake bar.
This sort of strategy has been used to fake gold bars. Tungsten is the metal used in this case. Both have the same density. A large lump of tungsten is placed in a mold for gold, which is poured around it. I can't figure how you would detect a fake with this strategy, if the stampings on the bar are genuine.
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Pillar of the Community
Canada
1502 Posts |
only way to know for sure is to rip one apart
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Valued Member
United States
264 Posts |
@jeffnash, I suggest taking some digital photos of the front/back/side of the bar and posting them here. We can often spot counterfeits by the type of stamping used on the serial numbers (if any). You should also note that the plastic case could be your best way of authenticating the bar. Sunshine mint uses a proprietary process for laminating these cases and forgers often will not go through the trouble. Even if they do, the edges will not appear like a usual piece of Sunshine mint plastic casing. Good luck and look forward to seeing more silver photos!  |
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Pillar of the Community
United States
4008 Posts |
Quote:
A large lump of tungsten is placed in a mold for gold, which is poured around it. I can't figure how you would detect a fake with this strategy, if the stampings on the bar are genuine. There are a few ways to do this but you need access to some sophisticated scientific equipment. A university lab with a friendly / co-operative chemist could do the job via x-ray diffraction analysis. Even if two materials are the same density their x-ray diffraction patterns will be different if they are composed of differing materials. Of course, this IS an expensive machine and will only come into play for such things if you know someone who is willing to do you a favor. Otherwise, renting the machine and the chemist to run it will likely be too expensive unless big bucks are at stake. A more destructive method involved drilling a tiny hole into the bar, collecting the drill turnings, and analyzing them via atomic absorption spectroscopy. Real gold will show a single large peak at the correct position on the scan for gold plus a few small contaminants typically found in gold. Tungsten, not being one of these, would show up in a different position on the scan like a huge red flag. Unfortunately, we do not yet have a tri-corder available for cheap to do such work. :-/ |
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Replies: 8 / Views: 7,440 |
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Posted 02/22/2012 9:23 pm
