If he tried selling the bars again the next day, then you've got a pretty good case that he's knowingly selling fakes.
Him immediately lowering the price is a huge red flag, and always weigh the bars! Anything under weight is a huge red flag, no legit bar should weigh even 31.0 grams. Sometimes they will be over, but I've never heard of a legit minter having their bars (or rounds) under.
This scares the you know what out of me ... I haven't bought much bullion by most people-on-here's standards, but the money I have put in, wow ... even the "infallible" magnet test isn't safe anymore. Maybe there's a test that can take into account specific gravity or maybe I need to invest in a good set of calipers to determine the density of the items I buy. I already have an acid testing kit but boy would I hate to scratch up all that pretty bullion, but that's what it is, bullion. I'm gonna go take a breather and think about testing all my rounds. Oh having to scratch up my 5oz libertad!!! NOOOO!
I would think if it's deep enough. I've bought bullion on eBay a few years ago, but all from reputable sellers (not that this precludes unknowingly selling fake items). The rest of the bullion I've bought has been from either Apmex, Provident, Panda America, and Silver Towne. I would hope they aren't getting duped either. I should be safe. That post was more or less my first reaction, like OMG this is getting out of hand. None of my bullion pulled on a magnet so that's good. I tested that whenever I purchased. But it couldnt hurt filing a bit from the edges to take a small acid test, especially on common bullion (not doing it on my Britannia or Libertad, just can't do it)
I did a search and see these bars for sale on CL in Hartford CT. What is the phone number you had for this guy? PM me, I'll give you the phone that is listed on the ad. HOTN
The density of an element is constant (most times). Assuming a solid, such as a coin, round, ingot, etc, knowing the volume and mass, you can determine the density (M/V or kg/m^3). You can then compare your results with those found in various tables published. From what I remember from Intro Chem and Organic Chem, the density can change slightly with pressure and temperature but this really only applies to gases. The amount of change is normally negligible when dealing with solids (as well as liquids). You can use some of the ideal gas laws to see the effect of such, but on solids/liquids it doesn't work quite the same way. edit: Here is a specific gravity test I think looks sound. Here is another demo, in video form.
It would do you little good if they use an alloy. Silver is not a dense metal like Gold or Platinum its density can easily be replicated with an alloy of base metals. There are youtube videos of fake pandas with weight and measurement that match up with real deal and user cuts them in half to show the interior metal is brass like color.
Remember "German silver"? People have been making imitation silver since the beginning of money. The English made up a whole bunch of fake Spanish milled dollars so that people would lose confidence in their competitor's money. They had copper in the middle. It's an old ploy. That's why people used to drop the coin to hear the ring. It's also why real silver is so valuable.
Life is a continuous lesson of learning. The best knowledge obtained is somethings through the most perilous experiences!
Just a quick update. I was contacted by an agent with the Secret Service, and met him along with another individual with the Department of Homeland Security. I guess there is an ongoing case for that person. I met with them and provided copies of all the info I could give them on my encounter. Luckily I saved everything, even all the voice messages that person left on my phone. Definitely some positive news, before getting their call, I thought the Feds weren't giving this any attention. It was pretty cool asking to see their ID's. ~JobIII
That is good news! Maybe they can get down the line a bit and find out who is distributing the bars to your area.
I usually buy silver small quantities at a time. And it is possible there make be a fake or two in my large collection. I certainly don't test every coin and bar. But I can tell you this.. If I were buying 150 bars from a single seller off craigslist, I'd test a few of them before handing over the money. I'd make them a deal, I'd say "I'm going to do some destructive testing on a few of these. If they are real, I'll buy the whole lot. If they are fake, I'll pay for the ones I damaged."
That surprised me a little, but then I thought about it from their perspective. Since the bars are of high quality, the government may suspect they are coming from a person or group with the capacity to counterfeit actual currency. A person with that level of skill is a sufficient threat, or should be considered one, worthy of serious investigation. Edit: The person making these bars should be very nervous at this point. The Secret Service is not a group to mess with. He or she will be caught.