Bitcoin cannot be filled with Tungsten

[cbeast]

We have that same risk with physical bitcoins.  

there are no physical bitcoins.

The term physical bitcoins refers to a method of using an offline storage medium for temporarily containing and masking the private key to a bitcoin address. Some devices are trustworthy enough for small amounts for them to be traded without online verification.

[barbarousrelic]

Use gold coins, preferably those under an ounce. Harder to drill, more work, less benefit, greater likelihood of getting caught than using 10 oz bars.

I am not 100% certain, but I would imagine that tungsten-filled coins would sound differently when dropped on a glass table than real gold coins.

[fivemileshigh]

Use gold coins, preferably those under an ounce. Harder to drill, more work, less benefit, greater likelihood of getting caught than using 10 oz bars.

I am not 100% certain, but I would imagine that tungsten-filled coins would sound differently when dropped on a glass table than real gold coins.

I think up to 100gr goldbars are safe for the moment. All the filled bars in the pics so far have ben 500gr and up.

[Luno]

If Tungsten ha higher specific gravity than Gold, they will have to mix The tungsten with something or the gold bar will be to dense!

[phatsphere]

If Tungsten ha higher specific gravity than Gold, they will have to mix The tungsten with something or the gold bar will be to dense!

the difference is extremely small: http://www.wolframalpha.com/input/?i=%28density+tungsten%29+%2F+%28density+gold%29

[barbarousrelic]

If Tungsten ha higher specific gravity than Gold, they will have to mix The tungsten with something or the gold bar will be to dense!

the difference is extremely small: http://www.wolframalpha.com/input/?i=%28density+tungsten%29+%2F+%28density+gold%29

Right.

Gold is 19.30 g/cc
Tungsten is 19.25 g/cc

So we're looking at a difference of 0.26%. On a ten troy ounce gold bar that's 311.25*.0026 = 0.81 grams if the whole thing is tungsten. Since some of it is real gold, the bar will weigh roughly a half gram more than it is supposed to, on a 311 gram bar.

What is the normal mass tolerance on a pamp suisse gold bar?

[phatsphere]

Since some of it is real gold, the bar will weigh roughly a half gram more than it is supposed to, on a 311 gram bar.

well, if it says 311 gramm, it will weight 311 gramm. what they change is most likely the size! i.e. a fraction of a mm on a non-even surface (where the embossed numbers and letters are) is impossible to notice.
therefore, one has to measure the actual volume, which is pretty hard.

[Desolator]

I'm somewhat certain that when gold buyers buy gold, they actually use two electrical probes that measure the resistance and if it's too high, it's not pure gold or it's plated whatever.  I suppose with that much thick surface gold or in the 2nd pic there, the electricity would simply travel around it in a significant enough level to not detect the tungsten.  Anyone know?

Btw I opened up my BTC wallet and found just a note that said my bitcoins' kidneys were missing and they needed to go to the hospital ASAP!

[casascius]

Bad news: I just checked one of my Bitcoins. I opened it up, and inside I actually found a LiteCoin!!!  This is a serious problem. I'm worried if I check my other Bitcoins the same thing will happen :/  Should I tell Gavin?

This is actually possible on a Casascius Coin, where someone can add Litecoins to it, and has been done before.

It is possible to compute the equivalent Litecoin address from the Bitcoin address with my Bitcoin Address Utility, and then it just uses the same private key.

[barbarousrelic]

Since some of it is real gold, the bar will weigh roughly a half gram more than it is supposed to, on a 311 gram bar.

well, if it says 311 gramm, it will weight 311 gramm. what they change is most likely the size! i.e. a fraction of a mm on a non-even surface (where the embossed numbers and letters are) is impossible to notice.
therefore, one has to measure the actual volume, which is pretty hard.

But does Pamp Suisse guarantee that their bars are 10.00000000000000000000 troy ounces exactly? Surely there is a tolerance, such as + or - .001 troy ounces Or .01 troy ounces.

[kjj]

Since some of it is real gold, the bar will weigh roughly a half gram more than it is supposed to, on a 311 gram bar.

well, if it says 311 gramm, it will weight 311 gramm. what they change is most likely the size! i.e. a fraction of a mm on a non-even surface (where the embossed numbers and letters are) is impossible to notice.
therefore, one has to measure the actual volume, which is pretty hard.

But does Pamp Suisse guarantee that their bars are 10.00000000000000000000 troy ounces exactly? Surely there is a tolerance, such as + or - .001 troy ounces Or .01 troy ounces.

No, they are cast into a form with a nominal weight, then measured very accurately.  They are then sold at their actual weight, not the nominal weight.

[Luno]

Ultrasound might work as long the tungsten is a bar or rods. What if the tungsten is a powder mixed in the inner portion of the gold bar?

maybe "Neutron Activation Analysis" would work: You shoot neutrons into the sample and Gamma ray energy, distribution and decay says something about the elements in the sample. It can detect even faint traces of other elements. Not for home testing, but quicker and less wasteful than recasting.

[totaleclipseofthebank]

Since some of it is real gold, the bar will weigh roughly a half gram more than it is supposed to, on a 311 gram bar.

well, if it says 311 gramm, it will weight 311 gramm. what they change is most likely the size! i.e. a fraction of a mm on a non-even surface (where the embossed numbers and letters are) is impossible to notice.
therefore, one has to measure the actual volume, which is pretty hard.

inb4 archimedes #eureka

[ErnestoJuarell]

My Bitcoins are filled with doubt

[phatsphere]

inb4 archimedes #eureka

his method is so inexact, it wouldn't work at all. you know, water has this nasty thing of "surface tension"

[dancupid]

I just wrote my private key onto a light bulb to test this - the private key was then projected onto my curtains when I turned the light on.
Tungsten and bitcoins are a dangerous combination.

[totaleclipseofthebank]

inb4 archimedes #eureka

his method is so inexact, it wouldn't work at all. you know, water has this nasty thing of "surface tension"

use oil then. this method should be pretty exact. Worst case you'd have to get some lab glassware to have precise volumetric measurements.

[MrTeal]

inb4 archimedes #eureka

his method is so inexact, it wouldn't work at all. you know, water has this nasty thing of "surface tension"

use oil then. this method should be pretty exact. Worst case you'd have to get some lab glassware to have precise volumetric measurements.

Getting accuracy of better than 0.1% might be pretty tough even with lab equipment, especially when one of the surfaces is embossed.

[Come-from-Beyond]

This is actually more wide spread than you think, I know lots of Chinese factories are producing
these tungsten filled "gold bars" that is flooding the market. Most of the time even the merchant would not
know, since it's difficult to know unless you destroy the bar and reveal what's inside. I think at least
20% of gold bars on the market right now, are tungsten filled.

Don't see any problem if these bars r used as legal tender. Noone should care what is inside. Tungsten is even more valuable than paper inside dollar banknotes.

[totaleclipseofthebank]

inb4 archimedes #eureka

his method is so inexact, it wouldn't work at all. you know, water has this nasty thing of "surface tension"

use oil then. this method should be pretty exact. Worst case you'd have to get some lab glassware to have precise volumetric measurements.

Getting accuracy of better than 0.1% might be pretty tough even with lab equipment, especially when one of the surfaces is embossed.

It would be pretty tough, you are right, and would require some laboratory skill. 19.25/19.30 is a thin margin.

The conductivity test or ultrasound would probably be the easiest.