Comments on: The problem of fake gold bars A slice of lime in the soda Sun, 26 Oct 2014 19:05:02 +0000 hourly 1 By: jclausin Sun, 08 Jun 2014 20:25:51 +0000 The best solution to remove the doubt is to control the ingots by a rapid and accurate method.
The best method of detection is to measure the actual conductivity of ingots.
for this, it is necessary to measure the electrical resistance and the geometric dimensions of the object, and this with extreme precision. The scanner CHECK GOLD developed by the firm JC-Engineering meets the requirements of control. In particular, the measurement when the tungsten content is in powder form, does not detect that the processes using the ultrasonic reflections.
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By: jimbostink Fri, 30 Mar 2012 18:49:51 +0000 Bars can be traced – so there is some risk in salting bars because eventually you will be found out.

By: danbemp Tue, 27 Mar 2012 15:18:47 +0000 Not to nitpick here but you’ve misunderstood Archimedes. A tungsten bar and a gold bar of the same volume will displace equal volumes of water as they both are entirely submerged. In fact, any object of the same volume with a density less than water will displace the same amount of water.

The point is comparing that volume to their mass, to arrive at their density. Tungsten and gold have very similar masses, but there is a difference. Take the mass of the bar (it’s weight), and divide it by the amount of water it displaced to arrive at density — that is the number that will differ.

By: BrPH Mon, 26 Mar 2012 21:39:59 +0000 I thought that the reason the bar was 2 oz short is probably that to make it the same weight, they would have needed to make it larger than a normal gold bar.

Looking up the density values of various elements I find different tables have different values. This one says Tungsten is higher density than gold, but not by much. Look up Chemix density element chart for a cute graph of how density varies by element.

Density Element
19.32 Gold
19.35 Tungsten
19.84 Americium
20.2 Uranium
21.04 Rhenium
21.45 Platinum
22.4 Iridium
22.6 Osmium

This chart shows density with Tungsten less than gold.
18.95 Uranium
19.25 Tungsten
19.282 Gold
21.02 Rhenium
21.46 Platinum
22.610 Osmium
22.650 Iridium

2 ounces of gold is 2.33 cubic cc, which is non-trivial.

I would guess that three things could have happened to screw up this thievery.

1. They used a density chart that was different than the density of the tungsten metal the thieves actually got hold of. Their tungsten was slightly lighter than gold, but they had planned that it be slightly heavier. But they couldn’t make the bar 2.33 cc larger than than normal.

2. The other problem the thieves didn’t think through is that when you drill out gold and insert tungsten, there will be voids in the bar that will make it lighter. Tungsten has a melting point of 3422 C. Gold has a melting point of 1064.5 C. If they had a regulation mold, they could pour molten gold on top of their drillout. But they couldn’t melt the whole thing, or they would risk having the tungsten block move and become visible. So there would still be air-voids, small, but significant. If they inserted the tungsten, then just soldered gold back over it, the air-voids would be a big problem. It would take an expert machinist to match the holes in the gold bar so tightly there would be no significant voids. But if the did that, then they might need to do their work in a vacuum in order to make it possible to push the perfectly fitted tungsten in.

I think that is where most of the 2 missing ounces came from.

3. The thieves could also have had one of their number stealing tungsten from them. Tungsten is $23 per ounce. Let’s say the thieves took 200 oz of gold from 300 bars and one of them pocketed 2 oz of tungsten per bar. That would be 60,000 ounces of gold, which they could sell at a price of $1600 per ounce for $96 million.

The thieves would need to buy $1.38 million worth of tungsten to do that. I volume, they could doubtless get a discount off the $23 spot price. The tungsten thief could net himself 600 ounces of tungsten, which he could sell for around $12,000 (presuming he doesn’t get the spot price).

The Achilles heel among thieves is that they don’t like to share. There would probably be three men, at the very least, 2. One of them would be the money man who fronted for the tungsten. He would expect to get almost everything. One would be an organizer, perhaps an assistant for the job. And one would do the actual hand-work. It is usually the case with criminals that the guy doing the hard work is not terribly bright, and gets the short end of the stick. They probably paid him a pittance for his work. Let’s say they were “generous” and gave him $50 an hour. Let’s assume one hour per bar, for 8 or 10 hours a day, two guys. So that low man on the totem pole would net $15,000 for his work.

But, the low man isn’t a complete idiot, and if he was cunning he would realize that the smart guys would be watching the gold like a hawk, but wouldn’t be watching the tungsten so closely.

So the low man could almost double his take. What does he care if the big guys get nabbed eventually for their score?

By: Abe.Froman Mon, 26 Mar 2012 20:08:31 +0000 Another question is how many bars in ETF’s are actually borrowed by their contributors and submitted to the ETF in return for shares to sell back to the retail investor? Whose property are they? Gold leasing is 0.5%-1.0% a year. If a bank contributed borrowed metal into an ETF, they sell shares back at 100% face-value, that’s a 99%-99.5% profit in the first year. There’s nothing in the GLD prospectus that bars this practice. They don’t ask where the incoming metal is coming from. I bet if you checked GLD’s bar list against Central Banks or Bullion Banks who lease metal, you’ll find duplicates.

By: Eericsonjr Mon, 26 Mar 2012 19:28:43 +0000 But how many salted nut bars think the tungsten bar of the exact same dimensions as the gold bar it replaces would displace a different amount of water?

By: youniquelikeme Mon, 26 Mar 2012 16:37:36 +0000 Who needs physical gold when you have a piece of paper that says someone ELSE holds your physical gold! There’s the ticket!

Thanks TFF, for the laugh, but some people take their gold veddy seriously (In India… you are blaspheming with that tongue!) but being Tungsten is used in the best quality darts, I think I favour the tungsten.

By: Christofurio Mon, 26 Mar 2012 15:58:04 +0000 I’d love to type something profound, but I’ve got to jump out of this tub and run about shouting “Eureka” for awhile now. I’ll be back — if nobody locks me up first.

By: reuterskostas Mon, 26 Mar 2012 13:08:02 +0000 The method of weighing the gold bar and then drop it in a pot of water and measure the volume diplaced was the method used by Archimides. This was he discovered that the jeweler who produced the crown of the king of Syracuse was a crook

By: OnkelBob Mon, 26 Mar 2012 12:51:05 +0000 Your solution of a Wheatstone bridge (micro-ohm meter) is flawed because the current used to do the measurements will find the the path of least resistance, which will be across the surface of the bar. Unless you were able to insert the probes fully into the tungsten, your values will equal the resistance of gold. I guess if you cranked up the amperage to the point where you saturated the the gold and the electrons had to cross the tungsten you could see the difference, but I also suspect you would see it from the puddle of molten gold and the solid tungsten core.
I believe a MRI would be quite effective. There would be a quite a difference of magnetic response at the region where the gold stops and the tungsten begins. You wouldn’t be looking at the pretty pictures but rather at the response curve.