Specific gravity test

[ChrisSilver]

Thought it was better to start a new topic for this...

This video was originally uploaded by HawkHybrid, thanks for sharing

http://youtube.com/embed/xYdSEAm-7uI?html5=1&fs=1

I am not a fan of this test simply because I don't wish to expose my silver to water as I am paranoid on my silver tarnishing, even if it is only for a few seconds I believe it will have an effect on the silver (even though maybe minuscule)

What are your thoughts on this test?

[HighlandTiger]

I've done it with a coin on a piece of thread, and discovered that my instincts were right, and I'd been sold a fake. I only did the test AFTER I found the coin to be slightly underweight, (diameter and width were fine). If a coin passes the weight, measurements and magnet test, then there is no need to do SG test, BUT if it fails on any of these I will always do an SG test. I had a sterling silver commerative coin from Birmingham mint, and it seemed to be a little underweight compared to the info I could find online. However I did an SG test and it came back a fraction under 0.925 silver. I just think in this case someone at the Birmingham mint may have had an offday mixing the silver and alloys together when it was minted. . But it was good enough for me.  

 

I used http://www.exonumi.com/?page=article&art=1 for working out the results. Oh and I don't use a paper clip, you can quite easily tie a slip knot round a coin that will hold no problem when lowering it into the water. And doing it by a steady hand instead of rigging up a scaffold is just as good. You may not get accuarate figures to the miniscule percent, but you will know if a coin is off or not.

[HawkHybrid]

have anyone had a fake that passed the sg test before?

 

HH

[HighlandTiger]

That's the good thing about a SG test, fakes CAN'T pass it. Well not unless you can fake silver with real silver

[Ares]

The perfect crime

[HawkHybrid]

to pass the sg test they need something thats heavier than silver to average

it out.

 

I was looking at the sg values and found tungsten at 19.6 and lead at 11.3.

 

tungsten is not used as the same weight in tungsten is worth 60x more when

pretending to be gold. that's leaves lead...

 

edit : http://www.csgnetwork.com/specificgravmettable.html

 

HH

[Pete]

Fake silver coins tend to be copper, nickel plated with an overcoat of silver.

Fake gold bars can have tungsten rods inside.

Tungsten is a fraction of the price of gold but it is also super hard - tungsten tipped drill bits for example.

I would imagine it impossible to stamp a coin from tungsten and milling a profile too costly.

Early fake gold coins used platinum - that would be a real find today !

It is impossible to fake a gold coin using base metals as the coin would ALWAYS be too thick for the correct weight.

Please correct me if you know otherwise.