I just bought some tungsten darts, and my friend told me all these stories about how scammers will paint tungsten to look like gold, or plate it with gold. Apparently they have similar densities, and so a gold plated lump of tungsten will weigh close enough to a piece of real gold to not be noticed. Is this a real scam, or is it something he just made up?
The densities are almost the same (a cubic centimeter of tungsten weights 19.25 g, a cubic centimeter of gold weighs 19.30 g). And the current cost of tungsten is $19.85 per pound compared to gold at $1,248.65 per pound. So it seems plausible that some people have tried selling gold-plated bars of tungsten as pure gold.
Yeah, absolutely.
The densities are different by only 0.3%, so you have to be pretty careful in checking the exact mass and volume of a coin (for example) in order to tell the difference. It’s definitely not something that you can tell by holding the coin in your hand.
Troy ounce.
Yeah, gold is more like $15,000 per pound.
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Adding a little bit of osmium , a metal with density 22.59 , into the tungsten could easily adjust the density to be accurately enough that of gold… osmium is approx 1/4 the price of gold, so won’t blow the budget.(you can still make a profit.)
Gold plated tungsten jewelry is made and often passed off as gold.
You can always give it a bite.
Pure gold is soft enough to leave a mark. Tungsten is very hard.
I think you’re low-balling the price of tungsten a bit, from this article “Market Price, Pure or Alloy & the Delivery Form”:
But remember what the song said, “… can’t tell the difference between the weight of gold from the weight of lead”
I saw a program on this a year or so ago. What the fraudsters do is rather more than plating. They wrap the tungsten in a good thick bit of gold - several mm or more - so that the gold bar passes scratch tests and bite tests and has a better feel. It showed that gold bars now get tested with something that will show up any tungsten bars or rods inside.
Good luck with that: osmium (specifically osmium tetroxide) is highly poisonous.
It isn’t as if the problem is either unknown or difficult to find.
This Chinese companyoffers such products for sale - with arguably a couple of only slightly contrived legitimate use cases.
Note, I tend to feel that this link might stray a bit close to the edge, but 30 seconds of Googling will find it cited on legitimate news sites. They make nothing illegal, just something with the potential for committing fraud. Mostly they just make stuff out of tungsten.
And highly stinky.
I have a number of obviously fake gold doorstops.
Consider melting points. Tungsten and related metals have melting points over 5000 degrees Fahrenheit. Gold melts at a far lower temperature.
Unfortunately, what you’d really want is a test that’s destructive to the counterfeit but not to genuine gold. If it’s real gold, you probably want to keep it intact, as the King of Syracuse did.
Makes me wonder: what’s the best (fastest/cheapest/requires no special instruments) non-destructive method to test an item, purportedly made of gold, for its purity? Heat capacity? Magnetic or electric properties? Neutron scattering?
(Well, I’m aware that the latter would, indeed, require some lab equipment…)
Sure, some few people wear “24kt” gold (usually actually 22kt) but 14kt doesnt bite that well.
Actually the bite test is to test for gold plated lead, which does bite. (This is disputed)
I can’t imagine a no-specialized-equipment solution. As a previously highly experienced NDT person, here’s what I’d do: first, obtain a known gold sample identical in size and shape to the object suspected of being gold. Then xray the known sample with some plausible KV and mAS setting and measure the resulting density this produces on a piece of xray film (or digital equivalent). Then do the same thing to the object suspected of being gold. Any non-gold inserts should be easily detectable on the film, and if the density of the image on the film varies from the density of the known-gold image, then there you go.
I’m not sure it was x-rays, but the program I saw showed them doing something like that. They had a portable wand thing which was connected to a monitor and they dragged it along the gold ingot. Tungsten inclusions showed up quite clearly.