# Fraud with Gold of 18K



## MartinMartinez (Feb 17, 2013)

Good evening

Yesterday came'd my friend that works in Jeweler's shop here in Montevideo(Uruguay)

He told me A curious case about Fake Gold Scam.

Last week comed a man with Gold Chain of 25 Gr weight.

He told that he want to sell it, The Chain had grab Tiffany&Co and 750 Germany on the lock.

My friend went to check it with Acid Test of 18K, *the result was positive of 18 K gold.*

So he paid him the money and the man leave'd.

After my friend melt the Chain and he saw that is just had many microns of Gold Plating.

He discover'd that its were of Stainless Steel,

So he don't understand how the man could swindle him with the chain, its impossible that the chain passed Acid Test.

And he not only scratched the chain in the stone and put the acid, he also apply the acid in the top of the chain to see if it real.

The only form its possible if the Chain may had MANY microns of Thickness of Gold plating( 20,30,40)


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## Palladium (Feb 17, 2013)

Did the customer ever handle, touch, or have possession of the chain again after your friend tested it?


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## MartinMartinez (Feb 17, 2013)

Palladium said:


> Did the customer ever handle, touch, or have possession of the chain again after your friend tested it?



No, he just give it to my friend because he wanted to sell it, he told him that it 18 K Gold,My friend Test it with Acid and its pass the test so my friend weight it and give him the money.


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## Geo (Feb 17, 2013)

it seems your friend didnt scratch deep enough. when testing, its always a good idea to visually check the metal as well as acid test. he may have spotted the white metal at the scratch test with a loupe.


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## MartinMartinez (Feb 17, 2013)

Geo said:


> it seems your friend didnt scratch deep enough. when testing, its always a good idea to visually check the metal as well as acid test. he may have spotted the white metal at the scratch test with a loupe.



Yes,but you never will know if the Chain has more than 30 microns of gold plating(IS VERY THIN GOLD PLATING)


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## RikkiRicardo (Feb 17, 2013)

Hi
now a days 
cut the the chain so that you can do a test the chain will not be resold then test
this scratch and test is good but only if you do it right there are so many people out to rob you in this business
never trust the marking lots of fakes 
as your friend is a pawnbroker he don't have the time to check every piece as it comes in only with the touch stone 
if it's heavy plated and he don't scratch deep enough it will be his lost 
tell you friend to cut a piece of the chain then test it with nitric experience will let him be a better buyer
everyone here will tell to tell your friend to be more careful
we have a lot of people on this forum that buy and sell from the public that can give you advice there si lots of tricks of the trade to catch
the frauds.

Rikki


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## MartinMartinez (Feb 17, 2013)

RikkiRicardo said:


> Hi
> now a days
> cut the the chain so that you can do a test the chain will not be resold then test
> this scratch and test is good but only if you do it right there are so many people out to rob you in this business
> ...



Yes, but they can't broke the chain to see if it gold or not, they have normal acid test.

My opinion is that the chain had VERY thin gold plated,so if the chain has more than 30 Microns of plating is difficult to see the difference.


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## philddreamer (Feb 17, 2013)

Martin, that's why you MUST file deep into the chain, and then test with the proper acid. A magnet, sometimes, also can give a clue. If you don't want to loose money, you must do the proper testing! If the person "selling" the item doesn't allow you to test properly, DON'T BUY IT! 
Phil


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## Palladium (Feb 17, 2013)

http://goldrefiningforum.com/~goldrefi/phpBB3/download/file.php?id=1765


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## its-all-a-lie (Feb 17, 2013)

55+ grams, total gold content less than 1/10 gram


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## Palladium (Feb 17, 2013)

PM sent. :twisted:


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## its-all-a-lie (Feb 17, 2013)

:mrgreen:


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## its-all-a-lie (Feb 17, 2013)

Acid test said it was 18k, magnet said otherwise.


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## FrugalRefiner (Feb 17, 2013)

MartinMartinez said:


> Geo said:
> 
> 
> > it seems your friend didnt scratch deep enough. when testing, its always a good idea to visually check the metal as well as acid test. he may have spotted the white metal at the scratch test with a loupe.
> ...



Martin,

I totally agree with Geo on this. I've scratched a fair amount of gold. If I suspect gold plate, I make a series of lines right next to each other on the stone using a sharp edge or corner of the piece I'm testing. I keep the lines separate, but close together and one right after the last like a series of IIIIIIIIs. Before I apply any acid to the stone, I use a 10X loupe and look at the edge I've just scratched. You can usually spot any difference in color between the yellow gold plate, and the copper colored or white base metal. A few scratches on a stone will go through a LOT more than 30 microns. If it still looks yellow, I add the test acid to the stone. By keeping the original test scratches separate, I can see if the first line or 2 react differently than the last line or 2.

I suspect the item your friend tested "passed" the test because the base metal in this case was stainless steel. He may not have seen much of a reaction from stainless on his stone, as compared to a copper alloy base metal. If he had examined the item under good light with a good loupe, he might have avoided this mistake. Trust (the acid test), but verify (with a visual examination).

Dave


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## philddreamer (Feb 17, 2013)

I bought some jewelry a couple of days ago, and there was a men's "gold" nugget ring. My grandson thought it was gold because it was stamped 14k. I told him, no way!
From the moment I saw it I knew something was wrong with the color; I was 99% sure it wasn't gold. So, after testing it for him... it was brass! 
Phil


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## Dan Dement (Feb 17, 2013)

An Alpha Mirage Specific Gravity scale will catch these type of items in less than 10 seconds and be non destructive. Get the bigger one! I did a group buy about for 20 of them about a year ago. It is really only accurate on solid items and if it off,it is off in your flavor. I have two and use them both many times a day. Along with my XRF, you can fool one but it's difficult to fool both.

Dan


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## etack (Feb 18, 2013)

MartinMartinez said:


> Geo said:
> 
> 
> > it seems your friend didnt scratch deep enough. when testing, its always a good idea to visually check the metal as well as acid test. he may have spotted the white metal at the scratch test with a loupe.
> ...



30 microns thick plating is quite thick. its .00118 inches thick or 1182 micro inches thick plating. I have some slip rings right now with plating at around 75 (or better) micro inches and I'm in love with them. If it was this thick the stone might have had some trouble with it. 

Eric


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## Chiptech81 (Feb 18, 2013)

I have carried out tests on stainless steel as a jeweller friend advised me of this sort of thing happening. Acids will pass as gold on stainless steel. Practise Filing into stainless steel and (true)18ct gold you will no how different it feels. Also the only magnets i use now as another tests are the magnets from old hard drives. I have noticed some cheap magnets not being strong enough to detect all base metals. There is an acid bottle test i have that distinguishes between platinum and stainless steel.
If you get caught once you will never make the same mistake again.


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## alexxx (Mar 9, 2013)

the classic "white gold" scam 
we see more and more 18k Italy stamped stainless steel pieces
stainless steel will not dissolve with the acid on a scratch test, it will 100% stay on the stone, even after wiping the stone with a cloth
18k gold will lightly dissolve after 5 minutes on a scratch test and when you use your cloth to wipe the stone it will go away
Even a hard drive disk magnet wont magnetize the "good fakes"

the only way to differenciate 18k white gold from stainless steel on a scratch test is to wait approx 10 minutes to see if the acid works on the base metals, if the scratch marks remains intact = stainless

be carefull when buying white gold


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## butcher (Mar 9, 2013)

stainless steel is a hard metal to file drill or cut gold and silver are much softer metals, when you file it for an acid test the hardness should be a clue, something is wrong when the file glide across and does not bite into the metal.

Maybe here the ole bite on it test, would let you know :twisted:


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## Chiptech81 (Mar 10, 2013)

alexxx said:


> the classic "white gold" scam
> we see more and more 18k Italy stamped stainless steel pieces
> stainless steel will not dissolve with the acid on a scratch test, it will 100% stay on the stone, even after wiping the stone with a cloth
> 18k gold will lightly dissolve after 5 minutes on a scratch test and when you use your cloth to wipe the stone it will go away
> ...



With the correct acid bottle that tests for platinum or stainless steel, it only takes a few seconds to get the result.
Just thinking of the owner of the shop as i know you cant expect customers to wait about 10 min just to get a test result.


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## badran106 (Oct 17, 2013)

hi all....i got cheap sheap scrap 18c white ...they are slightly magnetic cut in them about 1 milimeter deep and there were a lot of black on them...passes the 18k easy and turn black on 22k acid leaving acid yellow....on oxy fire they at first went white and melt in parts leaving black in black...please if you know the answer tell me and i thank you....i asked for platinum acid it should come sat.and will get chlorine next week..


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## gubni (Oct 22, 2013)

If it's a big item I do 10 rub tests and put acid on the 10th one.


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## justinhcase (Mar 1, 2014)

I got taken by a Tungsten filled ring last month.
There was a layer of good 18ct gold at least 3mm and then this large Tungsten ring it had all the right marks and no hint it was filled..
I only found the ring when I went to empty out my amalgamatio into shot.
It was in a lot of ten rings I bought off a local second hand shop and there is no way of knowing if he knew he was passing on filled kit.
It fooled me so how can I have a go at some one else for the same mistake I made but it is a very costly thing to have happen.
I am thinking of upgrading to one of the electronic gold testers as they say they can detect such things.cant afford an XRF yet.


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## jimdoc (Mar 1, 2014)

justinhcase said:


> I got taken by a Tungsten filled ring last month.
> There was a layer of good 18ct gold at least 3mm and then this large Tungsten ring it had all the right marks and no hint it was filled..
> I only found the ring when I went to empty out my amalgam into shot.
> It was in a lot of ten rings I bought off a local second hand shop and there is no way of knowing if he knew he was passing on filled kit.
> ...




Electronic testers and xrf only test the surface. You will be better off using a file to make a deep notch or simply cutting the item in half, in my opinion.

Jim


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## FrugalRefiner (Mar 1, 2014)

justinhcase said:


> I only found the ring when I went to empty out my amalgam into shot.


Amalgam?

I'm hoping you're using the word in the sense of it being the combination of what you had in your batch. Not rying to put you on the spot, but amalgam has a pretty specific meaning in recovery and refining. I'm just wanting to make sure you're not working with mercury, right? I'm sure you're not, but I want to clarify for others who may read this thread later.

Dave


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## justinhcase (Mar 1, 2014)

That was what i was curious about.
a lot of the electronic testers say they can Identify non-gold, gold plate, or gold-filled specimens.
And as the trend seems to be thicker and thicker layers of gold it is very hard to get a client to sit still while you hack away at what is still there property with a file in order to find out definitively.
A good unit looks to cost £300+ but if it only finds two or three heavy items where deep filed it would pay for itself.
I just did not want to be the one to fork out the £300+ to find out and was hoping the company's marketing the units where not being as dishonest as the chaps doing the filled rings and coines.


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## goldsilverpro (Mar 1, 2014)

Every definition I found for "amalgam" said it was an alloy of mercury and something else. So, I guess all amalgams are alloys, but not all alloys are amalgams. If it's an amalgam, it contains mercury.


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## justinhcase (Mar 1, 2014)

Yes sorry I know I was using it as short fo amalgamation.I have worked on my own for to long and have amde up a lot of short hand.I will try to be more precice.


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## jimdoc (Mar 1, 2014)

justinhcase said:


> Yes sorry I know I was using it as short fo amalgamation.I have worked on my own for to long and have amde up a lot of short hand.I will try to be more precice.




So, are you actually using mercury, or not?


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## justinhcase (Mar 1, 2014)

No I dont use mercury in my amalgimations though I suppose some might come from the base of crowns and such which some times look like the gray in fillings..


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## goldsilverpro (Mar 1, 2014)

justinhcase said:


> No I dont use mercury in my amalgimations though I suppose some might come from the base of crowns and such which some times look like the gray in fillings..


No mercury, no amalgamation.


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## justinhcase (Mar 1, 2014)

In general, amalgamation is the process of combining or uniting multiple entities into one form.As this seems to cause some confusion with my colonial friends I will desist in using the term in it's original early 17th century form: from medieval Latin amalgamate 'to formed into a soft mass', from the verb amalgamare.
sorry for any confusion I cover a good meany disciplines and am self educated.unfortunately what a word means in one discipline is often transposed with alternative meanings in an other.


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## goldsilverpro (Mar 1, 2014)

https://www.google.com/search?q=amalgam+chemistry+definition&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-USfficial&client=firefox-a&channel=sb

I read 10 or 15 of them and I'm 100% convinced you must have mercury to have an amalgam, as far as the modern chemistry definition is concerned. You don't even have to go to the sites. Just read down the Google search list and you see the word mercury in almost every entry.

I like this one the best. He doesn't seem to think that an amalgam is a true alloy, which is the same position I've always held. Most of this depends on definitions, as does any technical discussion.

http://www.stanford.edu/~bcalhoun/amalgam.htm


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## justinhcase (Mar 2, 2014)

Being schooled by Catholic priests has it's advantages particularly with root language.something google has not found an ap or search bar for.As much as I like to discuss syntax.
the string was meant to be about detection of hard to identify filled items.
The afore mentioned word was simply in a description of the discovery of a tungsten ring.
I personally would always describe a toxic complex compound or alloy in detail leading that description with the most toxic component.A term coined in the 1800's when there was a less empirical understanding of matter is open to misinterpretation.
But getting back to the original query do you think any of the electronic test set's that say they can detect deep filled items actually work or will we have to keep hacking thing's in half


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## jimdoc (Mar 2, 2014)

Specific gravity tests come in handy.

Jim


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## justinhcase (Mar 2, 2014)

Specific gravity is useless with tungsten.
Thank Gia I don't have enough triad to be dealing in large bars.
Have you seen all the drilled and filled bullion that has been turning up from repeatable traders.
That is very scary the losses on a ring seem trivial in comparison.
And the only way to be sure seems to be destroy and recast.


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## jimdoc (Mar 2, 2014)

justinhcase said:


> Specific gravity is useless with tungsten.
> Thank Gia I don't have enough triad to be dealing in large bars.
> Have you seen all the drilled and filled bullion that has been turning up from repeatable traders.
> That is very scary the losses on a ring seem trivial in comparison.
> And the only way to be sure seems to be destroy and recast.




Pure gold and tungsten are very close in specific gravity, but I think if it is a solid tungsten core inside of what is supposed to be 18K or 14K, I would think there should be a noticeable difference? 

Jim


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## justinhcase (Mar 2, 2014)

You are right there should be about 4g extera weight for every cubic centimetre of gold replaced on 18ct.
will have to set up a realy sensitive displacement tank and try.
No dought some one in china will start to produce tungsten alloy with specific gravity to match crated gold. that will be fun.


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## Harold_V (Mar 2, 2014)

justinhcase said:


> Yes sorry I know I was using it as short fo amalgamation.I have worked on my own for to long and have amde up a lot of short hand.I will try to be more precice.


The word you are seeking is alloy, not amalgam.

Harold


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## justinhcase (Mar 2, 2014)

thank you I will amend my diction to the local norm.
but not to labor the point.if you read the story at the time there was the alloy that was created the tungsten ring that had been left and considerable amount of flux in the crucible at the time.
This being multiple entities combined into one form I thought that it would be acceptable to use the abbreviated word for amalgamated to describe it.I am aware that in dentistry the term amalgam implies exclusively to a mercury alloy but in business and the military it can be used to describe the coming to gether of different components.and in engineering we would never use such a loos term with out specifically calling it a mercury amalgamation.
So very sorry for the guff please forgive me.


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## Harold_V (Mar 2, 2014)

justinhcase said:


> This being multiple entities combined into one form I thought that it would be acceptable to use the abbreviated word for amalgamated to describe it.


In a metallurgical sense, no, it isn't appropriate, as in that field, amalgamation is the combining of metallic elements with mercury (such as silver, tin and copper to form dental amalgam). To misuse the term is to imply that mercury is a part of the total, and it clearly is not. As I said, what you are describing can be considered an alloy, or even a solution. Unless mercury is involved, it is NOT an amalgam. 

If I am mistaken, please point me to the proper source of information. 

Harold


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## butcher (Mar 2, 2014)

I probably have used the word amalgam in a sentence where it should not have been used, and I should have used the term alloy.

Amalgam

Amalgam from the Greek words for together, to join.

An alloy of mercury with another metal that is solid or liquid at room temperature according to the proportion of mercury present . 

A mixture of different elements.

Synonym a mixture
a mixture or combination: {His character is a strange amalgam of contradictory traits}. 

When the word is used to describe metal alloys, it does look like mercury is involved in the alloy.
where mixture of metals alloys can occur by contact with mercury normally without heat, where the mercury acts as a solvent in contact with other metals, mercury being a liquid metal at room temperature.

Amalgams seem to involve mercury (I could not find any alloys described as amalgam that did not), mercury amalgams with many metals without heat in order of ease, gold, silver, lead and tin, mercury will amalgam with most all metals, In fact every known metallic element, excepting only platinum and iron, dissolves in mercury, at one time, mercury was stored in iron bottles. but is difficult to mix copper, it will mix with copper when heated to a high heat, or if mercury is in an oxidized state.

Even the alkaline earth metals, such as calcium, strontium, and barium can form compounds in the amalgamation process. Also, ammonia forms a very reactive amalgam.

An amalgam is more than a solution. A solution is comprised of one or more substances dissolved in one or more other substances called the solvent.

some examples, silver amalgam used in dental work, tin and mercury used for mirrors, gold or silver amalgams in mining recovery of metals, most all of these processes are outdated, and new safer and better processes have replaced or are replacing the amalgam processes.

The Difference Between an Alloy and an Amalgam - 
by Professor Xu Wang of the University of Akron 
An interesting read on this subject:
http://www.its.org/node/5666

I will try to use the words or terms amalgam, and alloy where they should be used, now that I understand them a little better, thanks.


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## kurtak (Mar 2, 2014)

justinhcase said:


> But getting back to the original query do you think any of the electronic test set's that say they can detect deep filled items actually work or will we have to keep hacking thing's in half



Not that I am aware of - the acid/electronic test set's will only tell you the exposed surface it is testing so even if you scratch the item being tested it will only tell you the new exposed surface

An XRF will read a bit under true surface but only enough so that it will tell you it suspects "possible" plating & in order for an XRF to tell you that you need to let it read the item for a couple minutes 

Kurt


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## justinhcase (Mar 2, 2014)

The Amalgamated Transit Union is a labor organization in the United States and Canada that represents employees in the transit industry. Established in 1892 as the Amalgamated Association of Street Railway Employees of America, the union was centered primarily in the Eastern United States; today, ATU has over 190,000 members throughout the United States and Canada.

Amalgamation is a now largely archaic term for the intermarriage and interbreeding of different ethnicity or races. In the English-speaking world, the term was in use into the twentieth century. In the United States, it was partly replaced after 1863 by the term miscegenation. While the term amalgamation could refer to the interbreeding of different white as well as non-white ethnicity, the term miscegenation referred specifically to the interbreeding of whites and non-whites, especially African Americans.
The term amalgamation was derived from metallurgy (see amalgam). It has been linked to the metaphor of the melting pot, which also originated in the US, and which described the cultural assimilation and intermarriage of different ethnicity. The intermarriage of whites with African Americans and, to a lesser degree, other non-whites was until recently in social disfavor in the United States, despite the long history of informal liaisons between white men and nonwhite women during the long years of slavery and after emancipation. Until 1967, interracial marriages were prohibited in many US states through anti-miscegenation laws.

A merger, consolidation or amalgamation, in a political or administrative sense, is the combination of two or more political or administrative entities, such as municipalities (in other words cities, towns, etc.), counties, districts, etc., into a single entity. This term is used when the process occurs within a sovereign entity.


the amalgamation of church and state
The principle of separation of church and state is documented in the first amendment to your constitution. Its importance derives from the historical fact that state sponsored religions have been a primary source of tyranny in numerous countries and societies. your founding fathers wanted to avoid any possible occurrence of an alliance of religion and civil government there, and thus the constitution strictly prohibits the establishment of a favored religion in your society.

But as I say sorry for using a term for its meaning out side that set out by Hook.
By the way is she the only female contributor??pity as her methods give me the horn


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## niteliteone (Mar 2, 2014)

From what I understand;
An "Amalgamation" has many uses in language and basically means "combining stuff"
An "Amalgam" is specifically a mercury + ___ metal combination when dealing with metals.

On this forum specific and proper usage of vocabulary is mandatory to avoid mistakes or worse.
The word was used improperly from the beginning and no amount of ___ can excuse that.

Lets get back on topic 8)


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## justinhcase (Mar 4, 2014)

Just seen again Amalgamite the award winning invention!
I knew I had seen the dreded word used in a syntax before not to do with Hg.


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## kurtak (Mar 4, 2014)

It doesn't matter how its used elsewhere ---- here it means mercury is in the mix

Kurt


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## Geo (Mar 4, 2014)

justinhcase said:


> Just seen again Amalgamite the award winning invention!
> I knew I had seen the dreded word used in a syntax before not to do with Hg.



This issue has been put to rest. To persist might risk you seeming to be disruptive. The forum should be considered a class room and should be treated like one. We all come here to learn and we learn from the people that know and already have the experience. The coarse of action is clear, when you are talking to your friends and acquaintances about refining, you can describe it as you please. While you are here, please use the accepted terms from the forum. It helps to alleviate confusion of having multiple names for a single object or concept.


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## justinhcase (Mar 4, 2014)

sorry to cause offense .
I was enjoying a good debate with what I thought where people similarly engaged.
My last query was why they have named the lattes supposedly miracle method of gold extraction after a substance it douse not contain?
I always want to understand better and have a compulsion to ask why.
I beg your indulgence if I appear to have acted in ignorance.
and P.S. no offense but "because I told you so" has never been a valid scientific explanation to me.


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## cmiller92 (Mar 4, 2014)

I have seen a very similar thread where someone always needed to get the last word in, needless to say but I will anyway...they were banned. It might be wise to retract the last statement in your apology, our very respected and senior member, Geo, might take offense.


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## Geo (Mar 4, 2014)

No offense taken on my part. I apologize for sounding like i was chastising as thats not my intention. I am not a moderator and don't pretend to be one. I am simply stating the facts and trying to give some direction. I would hate to see someone make a simple mistake and then add insult to injury by not taking the suggestions to let something go before it escalates. If anyone thinks that i have overstepped my boundaries, they should let me know and I'll try to modify my behavior to better suit them.


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## butcher (Mar 4, 2014)

I actually found this amalgamation of thoughts, and ideas from all of the members, and this discussion about the metal amalgam (with mercury), as opposed to alloys very interesting, and educational. 

Although an amalgam of metal is a mixture of metals which includes mercury in the alloy, an alloy or mixture of metals without mercury just is not called an amalgam of metals, but is considered an alloy of metals.

Mercury is not the only metal that is liquid, and will dissolve metals at a low temperature by contact, gallium a metal that will melt in your hand, gallium will also attack most other metals by diffusion into their metal lattice, making a mixture of metals (an alloy, but. Here I suppose like mercury it would not be considered a true alloy, as the mix is probably not a solution "Per Se", but would be similar to how mercury and other metals form the mix of metals in the mercury amalgam).

I am not sure I understand all of this correctly but it is all just fascinating to me.

Many metals will migrate or form a mixture where they contact, at the grain boundary where a thin portion of the metals may transfer or share electrons, even other instances where metals or dissimilar metals in contact can act as battery's with galvanic action,oxidation and reduction can also occur on contact (with moisture and air, gases and liquids acting as electrolytes in some cases) (over time or faster under high heating) many factors, of the circumstance which results in a chemical reaction of metals in contact with each other ...

I am unsure if moisture or some form of electrolyte would even need to be involved, or just close contact through bonding is all that is needed, which seems to be the case in some instances).

Heating metals to high temperature where one of the metals melt, the lower melting metal will also dissolve the higher melting temperature metal it is in contact with, (like tin will dissolve gold at the melting point or soldering point of tin), this molten metal (tin in this example) lowers the melting point of gold where they contact, or when melting metals to form alloys we can the form mixture of metal and at a lower melting point of the metals involved in the mix, the metal with a lower melting will become the solvent for the other metal, and will melt (the higher melting point of metal in the mix, well below that of the metal with the higher melting point, gold here will melt at a lower temperature than the pure metal itself would melt. the alloy having a lower melting point than the metals involved in the alloy would on their own...

I do like this discussion and like learning where I should use the proper terms and why. With the why which is what I really like to know, sometime leads to me learning more about how these metals react with each other, and things around them.

Language (not only English) is a funny thing sometimes, I used to think it did not matter how or what you said, the whole point of communication was to understand each other.

When we all use the same term or meaning for an alloy or amalgam we will all understand each other better, and what we are discussing, improving our ability to communicate our meanings with each other, so my thoughts on language have changed somewhat, using the right word in the right place can help us to communicate and understand each other better. 

Being on a forum where we talk with a keyboard, and cannot see each other (making it even harder to get ideas across), communication of thoughts and ideas is harder, here words typed, and read are what we have to go by, making communication a bit more challenging, (misunderstanding each other easy), so if we all type the same word having the same meaning in mind we as readers do not misunderstand each other as much...

And Knowing why and learning more is the fun part of this science of metals.


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## g_axelsson (Mar 8, 2014)

butcher said:


> Heating metals to high temperature where one of the metals melt, the lower melting metal will also dissolve the higher melting temperature metal it is in contact with, (like tin will dissolve gold at the melting point or soldering point of tin), this molten metal (tin in this example) lowers the melting point of gold where they contact, or when melting metals to form alloys we can the form mixture of metal and at a lower melting point of the metals involved in the mix, the metal with a lower melting will become the solvent for the other metal, and will melt (the higher melting point of metal in the mix, well below that of the metal with the higher melting point, gold here will melt at a lower temperature than the pure metal itself would melt. the alloy having a lower melting point than the metals involved in the alloy would on their own...
> 
> I do like this discussion and like learning where I should use the proper terms and why. With the why which is what I really like to know, sometime leads to me learning more about how these metals react with each other, and things around them.


Prepare to learn some more then... anyone not interested in learning some physics better stop reading here. :mrgreen: 

In the first part you used the correct terminology, solvent. But then you started to talk about "tin is melting gold". That's wrong! Tin is dissolving gold at below the melting point of gold. Just as we dissolve metals in acid or sugar in water.
Melting is a quite well defined physical process and classified as a "first-order phase change" while dissolving something is a "second-order phase change".

Okay, I could go quite a lot deeper into theory but that would only scare away the few brave souls that read so far... The easiest way to look at it is to see what happens when you heat a closed system.

Melting : Take a block of ice from the fridge and place it in a pan on the stove. When heating it (slowly) the temperature will rise until it reaches the melting point of ice. There the temperature will be fixed until all ice is turned into water. Then the temperature will continue to rise.

Dissolving : Take a glass of water and add a hefty dose of salt so it becomes saturated. Now if you heat it more salt will dissolve while the temperature is rising. In this case the temperature is changing while the phase change (solid -> dissolved) is taking place.

So, first-order phase change then the temperature is fixed during the change, while second-order phase change changes temperature during the phase change.

So the correct term to use is "tin will dissolve the higher temperature melting gold" and if you saturate the tin with gold you can add heat and raise the temperature to dissolve even more gold.
"Gold here will dissolve at a lower temperature than the pure metal itself would melt."

Sorry, I guess the physics in me just raised it's ugly head. 8) 

Göran


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## butcher (Mar 8, 2014)

g_axelsson, 
Thanks I fairly well understand what is happening in the process, I do have a hard time putting it into words, a skill I have trouble with, thanks for putting it into words that make more sense, and use of correct terminology.

Dissolving metals with heat. I suppose all of those excited little electrons under that torch, with the hot foot dancing around, are very busy jumping to higher energy levels (or electron shells) in formation of the alloy.


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## Irons (Mar 8, 2014)

Chiptech81 said:


> I have carried out tests on stainless steel as a jeweller friend advised me of this sort of thing happening. Acids will pass as gold on stainless steel. Practise Filing into stainless steel and (true)18ct gold you will no how different it feels. Also the only magnets i use now as another tests are the magnets from old hard drives. I have noticed some cheap magnets not being strong enough to detect all base metals. There is an acid bottle test i have that distinguishes between platinum and stainless steel.
> If you get caught once you will never make the same mistake again.



There are stronger Magnets than those from Hard Drives. Type N 52 Neodymium Alloy seems to be the strongest available. I purchased a few a while back. They are expensive, but will pick up most Stainless Steel. I say most because there is at least one type of Stainless it won't pick up. It's used in Standard Testing Sieves. I don't know what type it is, but it has no detectable effect on the N52 Magnet. On the other hand, type 316 Stainless grabs with a strong pull.
Tungsten has no effect at all on a Magnet. The only way to determine if it is Gold is to use an Ultrasonic Thickness Gage. The velocity of the signal through Gold has a considerable difference, compared to Steel or Tungsten, and will show up as an error in the measured thickness compared to the actual thickness of the item in question. It's a very quick and non-destructive method of testing items. Small handheld units are available for under US $200.


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## Dan Dement (Mar 9, 2014)

Justin,

S.G. test will catch it. I have two Alpha Mirage S.G. Scales and it's at great test for filled bars,, rings, and chains. I have three years buying using an S.G. Scale and using XRF's. It has saved me from making expensive mistakes all the time. I am on my fourth XRF and have sold all the older machines to friends when a new upgraded model came out. When it comes time to cash out, it's useful indication but not as accurate as an good XRF and good masters. 

Dan


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## niteliteone (Mar 9, 2014)

Dan Dement said:


> Justin,
> 
> S.G. test will catch it. I have two Alpha Mirage S.G. Scales and it's at great test for filled bars,, rings, and chains. I have three years buying using an S.G. Scale and using XRF's. It has saved me from making expensive mistakes all the time. I am on my fourth XRF and have sold all the older machines to friends when a new upgraded model came out. When it comes time to cash out, it's useful indication but not as accurate as an good XRF and good masters.
> 
> Dan


How does it do with those Chinese bars that have been drilled and filled with Tungsten, then resealed :?: 
I've read more than one story of people getting reamed with them from sellers on ebay


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## justinhcase (Mar 10, 2014)

Thanks Chaps ,That is all really helpful
I will have to find or make some relevant examples of Tungsten filled Items and experiment further.
Particular thanks to Irons for the extra help with the ultrasonic velocity method.
I can see it would be a good service to offer to clients as well as use my self.


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## Tub Buster (Mar 19, 2014)

Ultrasonic testing is useful for bars and other standard shapes that can be calibrated.

Gold, stainless steel and tungsten are very different metallurgically. Gold is soft and malleable, stainless is significantly harder, and tungsten harder still.

Probably hardness would be the easiest parameter to test, as most jewelry is curved, and strain differs with geometrical shape. Google "hardness tester". A photo of a tester I use for lead is attached below.

Here are some values from http://www.matweb.com : Incidentally, this is a good site for determining composition of alloys, like dental alloys for example.

Gold:
Hardness, Vickers 25 
Tensile Strength, Ultimate 120 MPa 17400 psi Annealed 
Elongation at Break 30 % 
Modulus of Elasticity 77.2 GPa 11200 ksi 60% Cold Worked 
Poissons Ratio 0.42 
Shear Modulus 27.2 GPa 3950 ksi 
Electrical Resistivity 0.00000220 ohm-cm 
Magnetic Susceptibility -1.42e-7
====
Tungsten:
Hardness, Brinell 294 Estimated from Vickers. 
Hardness, Vickers 310 
Tensile Strength, Ultimate 980 MPa 142000 psi 
Tensile Strength, Yield 750 MPa
Modulus of Elasticity 400 GPa 58000 ksi 
Poissons Ratio 0.28 0.28 
Shear Modulus 156 GPa 22600 ksi Calculated 
Shear Strength 400 MPa 58000 psi Average value for W blanks. 
Electrical Resistivity 0.00000565 ohm-cm 
Magnetic Susceptibility 3.3e-7 
==========
316 Stainless steel:
Hardness, Rockwell B 69.5 69.5 
Tensile Strength, Ultimate 538 MPa 78000 psi 
Tensile Strength, Yield 200 MPa 29000 psi


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## Dan Dement (Mar 19, 2014)

Tub Buster,

I appreciate your science lesson but have you actually tried using a Vicker's or Rockwell tester? I have access to some Testers used in the Aircraft industry and I must say that the results are confusing at best. Usually you are not dealing with 100% metal but a fraud trying to cheat the honest people on this earth.

To answer the question would an Alpha Mirage Scale catch a Filled Gold bar? There is a difference between Tungsten of 19 SG compared to Gold of 17. I have never actually seen a filled bar but I would have to say Yes, I think it will. The latest scale actually gives you gold purity accurate to about 1%. The reading the scale on the Machine would give you is in excess of 24kt. I am not sure about you but I think my alarms would be going off. I am sure If I was the one trying to cheat people, I would come up with a mixture that will replicate pure gold. I don't know what that is but I sure it is possible. To be 100% honest, I don't know as I have not seen or bought one. . . . Yet!

Dan


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## Subin (Nov 6, 2017)

Hi Martin,
I also become one of the victim of gold scam today as your friend. Story was that, “ i was shopping grocery and a man approached to me holding 24k gold chain in his hand. He gave me the chain to have a look at and the gold was 24k only and was almont about 40gm. He ask $1000. I have a good knowledge of gold and I knew I would make more so I bargain the price to $600 and gave him the money. I was happy but when I came home I saw a fake gold chain. The point to note is that the chain that he showed me was pure gold but the gold chain I received was fake that means he actually suffled the pouch. The design of the chain was also different. 

So Martin, your friend may have not noticed the design and the pouch.


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## jimdoc (Nov 6, 2017)

Subin said:


> Hi Martin,
> I also become one of the victim of gold scam today as your friend. Story was that, “ i was shopping grocery and a man approached to me holding 24k gold chain in his hand. He gave me the chain to have a look at and the gold was 24k only and was almont about 40gm. He ask $1000. I have a good knowledge of gold and I knew I would make more so I bargain the price to $600 and gave him the money. I was happy but when I came home I saw a fake gold chain. The point to note is that the chain that he showed me was pure gold but the gold chain I received was fake that means he actually suffled the pouch. The design of the chain was also different.
> 
> So Martin, your friend may have not noticed the design and the pouch.




Martin was;
Last active: Sat May 18, 2013 10:03 am. Welcome to the forum.


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## nickvc (Nov 6, 2017)

Jim not to be pendantic but his post is dated 2014...


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## jimdoc (Nov 6, 2017)

nickvc said:


> Jim not to be pendantic but his post is dated 2014...



Where did you see that?
He was responding to Martin, not Dan.

Here is Martin's info;
http://goldrefiningforum.com/phpBB3/memberlist.php?mode=viewprofile&u=33576


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## Bramanda (Oct 10, 2020)

I'm all about diy(do it yourself ) techniquea; almost as creative as Magiver. Fill a cup/bowl/pot/ or whatever, & then drop the shiney bit in.


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