Strange marks 100g bar
- Thread starter Connor
- Start date
Golden ChipMunk
Well-Known Member
Test it with a Magnet first.
Magnet is easy to get hold.
Magnet is easy to get hold.
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Looks like fresh patina cause they may turn brownish colour then pitch black... wise to get it chk @ local dealer
BiGs
Active Member
If there is a line that goes all the way around the sides, then yes that is very suspicious and I'd be making sure it hasn't been hollowed, filled and silver soldered up.
Jewelers have the knowledge and tooling to do this very easily. That said, XRF and PMV will not penetrate to the core of a bar, 2mm max. So first I would try what Chip said and use a magnet, rare earth type if possible, plus weigh it and see how close to 311 grams it is (10oz bar?). The core would of unlikely been filled with a ferrous metal though (assuming it has been cored and done by a jeweler), more like lead, so a magnet will not pick that up. So failing the magnet test, if you do have access to an XRF or PMV, test the material along the line. Jewelers silver solder cannot be pure silver, its usually only majority silver, max Stirling level. So if there is discrepancy in purity along that line, at this point you should try your best to return and refund it to where you got it, saying it's dodgy AF. Failing that, I would shear it in half with big bolt cutters, if it really has been hollowed, reference consumer law and demand a refund. If you bought privately, and cannot contact, then try sell the silver that's there for melt value to salvage what you can.
If you know anyone in the NDT industry, it could also be ultrasonically tested without destroying it, which will test 100% the way through it for any faults at all. There is also spec grav test too.
If the marks don't go all the way around, then they might be just vault scuff marks. But for everyone, you should check your bars for these types of marks as guaranteed some jewelers do this to get a free supply of silver.
Jewelers have the knowledge and tooling to do this very easily. That said, XRF and PMV will not penetrate to the core of a bar, 2mm max. So first I would try what Chip said and use a magnet, rare earth type if possible, plus weigh it and see how close to 311 grams it is (10oz bar?). The core would of unlikely been filled with a ferrous metal though (assuming it has been cored and done by a jeweler), more like lead, so a magnet will not pick that up. So failing the magnet test, if you do have access to an XRF or PMV, test the material along the line. Jewelers silver solder cannot be pure silver, its usually only majority silver, max Stirling level. So if there is discrepancy in purity along that line, at this point you should try your best to return and refund it to where you got it, saying it's dodgy AF. Failing that, I would shear it in half with big bolt cutters, if it really has been hollowed, reference consumer law and demand a refund. If you bought privately, and cannot contact, then try sell the silver that's there for melt value to salvage what you can.
If you know anyone in the NDT industry, it could also be ultrasonically tested without destroying it, which will test 100% the way through it for any faults at all. There is also spec grav test too.
If the marks don't go all the way around, then they might be just vault scuff marks. But for everyone, you should check your bars for these types of marks as guaranteed some jewelers do this to get a free supply of silver.
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Please explain...
BiGs
Active Member
The XRF beam is limited to the isotopic material inside powering it. The typical XRF machines you see jewelers and gold buyers have (about a foot or so high in a case) have under the the limits of carrying radioactive material (harmless) and they only want to track possession. The beam these XRF machines produce will only go up to about 0.5mm deep into metal (about finger nail thickness), they will detect plated items anbd bring back the ingredients of the metal at the atomic level, but only to the beam depth. There is much powerful machines but you might see those in labs, or under more controlled conditions etc (with a lot more licensing involved) and not so portable. The PMV machines, according to their documentation can go to a depth of up to 2mm into metal using the wand, which amplifies the signal. I believe it uses two injunction technologies, ultrasonics and another one (eddie current maybe?), not sure. It will not provide atomic ingredients, but more calibrate it to one metal and purity, and it says yes or no. Simplified, but cheaper. XRF is needed for fine jewelry, PMV is best for bullion. Neither will see into the middle of a bar.
After the first sigma PMV came out fakers improved there game so Sigma had to improves there’s. A true arms race.
BiGs
Active Member
How much to buy a PRO with all attachments landed in aus would you say?
It’s around $2800. That includes the bridge which is great for the big bars of silver . Pays for itself in one dodgy transaction.
There is a guy in the USA selling on ebay but you will get hit with 10% import duties and the point of sale.
I purchased direct from sigma but it looks like they pass you on to a distributor now.
https://www.sigmametalytics.com/
https://www.sigmametalytics.com/
BiGs
Active Member
Yeah ok, about double the price of the first model if I remember correctly. Its a decent cost for the average stacker.
Yeah. I see now the PRO has the double probe feature and goes all the way through the sample and tests spec grav which is cool. A ultrasonic Chinese cheapee machine with calibration block will set you back about that price too, but it is much harder to use and you need to calibrate it to every bar you test. I wonder if they they are really using sound attenuation and calling it spec grav, same result, but harder to explain the process. They still very vague on the tech details I see haha.
So to correct what I said about PMV not testing the core of a bar, the PRO model does test all the way through.
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The bridge is about 800 from memory but i think it is a worthwhile buy, you could not get that if you were only buying coins or small minted bars
That thing looks like a worthwhile purchase indeed.
I don't recall PMV only goes to 2mm thickness... do you have the documentation on this fact...?
In SIGMA documentation link, it says thicker than 2mm, depending which wand to use based on thickness. Main sensor does > 2.4mm
https://sigma-verifiers.com/downloads/PMV_Original_Technical_Guide.pdf
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