Gold testing

[rioux]

Hi! Im a little confused about gold i get on ebay. I tested it whit 22k solution and it been etched relatively fast but the weight volume i calculated is about 19.3-20.8 g/cm2.

Here some pic.

 

[rioux]

it suppose to be 995 gold

 

[rioux]

Here the front side

 

[Topher_osAUrus]

it suppose to be 995 gold

Gold is 19 times heavier than water... There are less than ten elements that are more dense than it
Uranium 18.95
Tungsten 19.25
Gold 19.282
Roentgenium >19.282
Plutonium 19.84
Neptunium 20.25
Rhenium 21.02
Platinum 21.46
Darmstadtium >21.46
Osmium 22.610
Iridium 22.650
Seaborgium 35 (Estimate)
Meitnerium 35 (Estimate)
Bohrium 37 (Estimate)
Dubnium 39 (Estimate)
Hassium 41 (Estimate)
(from http://chemistry.about.com/od/elementfacts/a/elementdensity.htm)

So, if its 995, why would they put anything in it that is more dense?...id use copper or silver to lower from 4 nines to 995... But, maybe you have a kind soul seller... Doubtful.

What are you comparing it to when testing it?

Did you get a whole testing kit?
Did it have different karat testing needles?
How long have you had it?
How are you testing the density exactly? Is your graduated cylinder accurate? Is your scale? ...a couple mL and tenths of a gram make quite a difference ive found.. First graduated cylinder i bought ended up being 15 mL off...

 

[rioux]

I had it today.
Yes i have different testing solution but as it was suppose to be 995 i tested it only whit the 22k.

For the volume i mesured it whit electronic calpiler so the volume have a little mistake as there is some little sing on it but i evaluate +- 10% mistake at the max.

 

[Topher_osAUrus]

I had it today.
Yes i have different testing solution but as it was suppose to be 995 i tested it only whit the 22k.

For the volume i mesured it whit electronic calpiler so the volume have a little mistake as there is some little sing on it but i evaluate +- 10% mistake at the max.

10% can be quite alot. Have you had it shot with an xrf just to see what else may be in it?

 

[rioux]

I retested whit 10 14 18k only the 22k do someting... And i remesured it and it gived to me 17g/cm3 (that make more sense but hard to tell the volume my calpiler can mesure 1/100mm) but the corner of the rectangle of the gold ingot have circular corner and i dont want pass 2h by doing mesurement... And i waiting for 5ml cylinder...

So i retested whit the 22k to have some disolved gold and it have yellow and purple collor? Gold mixed whit platinum?

 

[rioux]

Lol i dont have xray machine :lol:

 

[patnor1011]

And how exactly did you tested it? Are you not using scratch stone? Why would they make 1g bar with Pt in it without marking it as such?

 

[Topher_osAUrus]

Do you have any copperas?

Test some of the solution with a crystal of ferrous sulfate and after the gold has ppt out, move the remaining test liquid (just use a little bit...) and then test with your stannous chloride

It does kind of look like that to me, but, i havent dealt with much Pt at all. So maybe another member can help with determining the mix of colors you have there. As knowing the SnCl colors, especially when mixed, takes a trained eye that has much experience... That, i have neither of.

 

[rioux]

No i dont have copperas i just have smb. But i have some ferrous board etchan for electronics but i dont think is the same than copperas

 

[Topher_osAUrus]

And how exactly did you tested it? Are you not using scratch stone? Why would they make 1g bar with Pt in it without marking it as such?

Excellent question to pose.

You may be able to find s local jewelry store with an xrf.

I would be willing to bet that isnt the same as ferrous sulfate, or if it is, it wouldnt be good for testing. Most gardening stores sell the hi-yield brand. Or butcher has a good post about making and storing some.

 

[rioux]

Ho sorry no scratch stone... The one i get is scrap now... (Newbee) but i would like to find a way to mesure volume for someting like 1g of gold? Is someone have any idea? I tink about pascal sensor and water to have something good.... Any developpment? So as pascal is 1newton/m2 if i use water and sensor able to mesure Pa i could know really little volume... I have some mecanical trouble usnolved... So im maybe to much curious about my little 1 gramm gold bar that is not pure...

 

[rioux]

I just ordered some 1/100ml pippet i tink it will help...

 

[solar_plasma]

Regarding the yellow discoloration: did you check your stannous chloride with standard gold solution? I guess it has only become old. With old stannous made from solder I sometimes got this yellow beside purple or black.

 

[Anonymous]

A couple of questions if I may.

1. How much did you pay for this?
2. What do you think about the colour change between the rubbed areas and the unrubbed areas?
3. Do you have any pure gold to check this against?

Jon

 

[rioux]

No i did not tested my solution yet but i already tested it 4 days ago so i expect its already good...
i paid about 64 cad i know is more than market valut but as i starting in refining i use it as a sample... that is not the best i had...
i really dont know about these area its why i asking i dont have the eye for it... but it a little stranger for me see 2 different color from the same solution sample.
yes i have some pure gold testing solution ill try it and come back

 

[rioux]

So my 4 days are over lol it wasent doing it before.... Thanks for the information.

 

[rioux]

But my stannous is not made from old solder but from (suplose to be) 99.99% Sn powder

 

[g_axelsson]

Doesn't matter what you make your stannous from, it can oxidize quite fast if not stored in a closed container. I've had stannous go bad in a few days when I had it in a beaker while my last batch have lasted me half a year and still is working fine. Now I always keep it in a small dropper bottle and it protects it from the oxygen of the air.

Göran