# Silver Testing Kits - Any Recommendations?



## Anonymous (Apr 15, 2008)

Hi Everyone,
A friend of mine has an old hand poured, 100 oz bar.

I'm not doubting that its not real... BUT... I'd just like to see for myself.

Can anyone recommend a good silver testing kit or an accurate method? I'm not a novice with chemicals so any method would work fine. I'm just thinking a kit may be a bit easier? 

Any suggestions or comments are welcome.

Thanks!


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## Anonymous (Apr 15, 2008)

If anyone is able to include the ratio for HNO3 + KCr2 + H2O AKA- Schwerter much appreciated.

Crude fineness testing is done with dilute nitric acid. Silver + dilute HNO3 yields a creamy white to brown liquid. Alloys containing Cu, Ni, and brass effervesce and yield a green, yellowish green or bluish green color. More precise technique involves gauging reaction and resulting color with Schwerter solution (HNO3 + KCr2 + H2O).
> Schwerter Salts. Schwerter's Testing Fluid is made by dissolving all of the Potassium Dichromate Salt in a solution of 3/4 oz Nitric Acid plus 1/4 oz distilled water. Mix well in a glass container to dissolve the salts then fill the small bottle of the kit. This is used for testing gold below 14 karat and detecting base metals.
>
> Testing Below 14 Karat and Base Metals with Schwerter Salts
> File a deep notch in the test piece and apply a drop of Schwerter's Solution in the notch. The colour reaction of the solution with the metal will be as follows:
>
> * Brass - Dark Brown
> * Copper - Brown
> * Nickel - Blue
> * Palladium - None
> * Gold - None
> * Silver Pure - Bright Red
> * Silver .925 - Dark Red
> * Silver .800 - Brown
> * Silver .500 - Green
> * Lead - Yellow
> * Tin - Yellow
>
>


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## peter i (Apr 15, 2008)

10 grams of potassium dichromate was what we ended at here:
http://goldrefiningforum.com/phpBB3/viewtopic.php?t=696&highlight=dichromate


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## Lou (Apr 15, 2008)

I would actually stay away from marring the bar if at all possible. 

Perhaps make a streak on some porcelain? If you add a drop of 20% nitric acid and the metal dissolves and gives a clear solution, it's likely silver. Add a few drops of 20% HCl and if any precipitate forms, then it's most likely silver. Add many drops of conc. ammonia and if the white precipitate dissolves, it is definitely silver.

Any green or blue and it's a base metal.


A good test for lead is to dissolve the metal in nitric and add a crystal of sodium or potassium iodide. If a yellow precipitate forms, there is lead.


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## Anonymous (Apr 28, 2008)

watch out for the larger bars out for the larger bars of silver!!!I know of a guy who buys silver and just bought a couple 100oz bars that ended up being hollow and filled with lead  Make sure its from good source and there are no questionable casting flaws on the bar :!: good luck in your venture


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## agpodt77339 (Apr 29, 2008)

To make sure it isn't filled with another metal, you could find the specific gravity or the density. Both methods are discussed on this topic

http://goldrefiningforum.com/phpBB3/viewtopic.php?t=1387&highlight=specific+gravity


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