I Need Help Identifying If This Is Gold Plated Or Not

[Anonymous]

Yesterday I received a package from an eBayer that I've purchased from on two occasions in the last 3 weeks. I received a message through my eBay account and he told me that he wanted me to check for gold plating on some pins/connectors. After replying to him, he told me that he had already sent them out to me (with USPS Confirmation) already.

Anyway, I received the package yesterday and I've done some testing on 3 of the pieces (31 grams weight) sent to me.

I believe the pieces are aluminum and have a copper coating. But that's where I need help because I'm not sure my testing methods can and do verify what he sent me.

I scanned just a few pieces of these

The three (3) pieces on the top right have been tested with 10K acid.

The results are this.....

* The pieces started foaming white and then they had a blueish/green color when the acid stopped reacting.
* After wiping one of the pieces off with a paper towel, the paper towel was blueish/green. I suspect copper coating.
* After testing three (3) pieces each resulted the same as the last.

I suspected that the base metal is aluminum. The reason I believe aluminum is because of these factors.
* The metal was a silvery color after the dark brown was eaten off the pins.
* The metal has a lighter weight to the whole group although they're 31 grams, but they are lighter than 31 grams of other pins I put in my hands and weigh.
* The metal doesn't make the sound that the other pins and other gold-plated items I have
* The metal feel softer to the grasp of them as a bunch, compared to grabbing a bunch of my other gold-plated pins/connectors.
* I took a cigarette lighter to one of the pins and after heating the ping for less than 30 seconds, it didn't drip melt, but it melted down, and the resulting color of it was silvery/white.
*Forgot To Mention I used a magnet and they are not magnetic


The pictures below are what he emailed to me after I informed him to give me some more info on the pins. The website for these pins are at: http://www.vishay

Any info in identifying the material of this will be greatly appreciated. I do think it's aluminum coated with a copper color or something brown, but not gold plated.

photo no# 1 sent to me

photo no# 2 sent to me

photo no# 3 sent to me

I asked him to take the tape off of the package on picture no# 2, but he said he used some mild solvents (I didn't ask what) and it took off the wording/information that was on it. He said is was a patent no#(s)

Can someone help me on this one?... I appreciate it.

 

[Palladium]

Cut one in half and drop it in hcl. If it aluminum you will know by the very quick reaction. If it eats the aluminum up and their is a foil left then it could be gold. The blue green you speak of is common for copper nickle alloys though.

 

[NobleMetalWorks]

Those look like amplifier pins to me...

I have processed a lot of that type of material, you can find them in amplifiers, hospital equipment, etc.

The older ones have Ag/Au/Ni/Cu

Newer ones have just Au/Ni/Cu

If they are the same type of pins, half will look like it might be Au plate, the other half looks like it is some type of white metal like Ni or Ag.

The yield is slightly better than just straight pins, if they are indeed Au plate because of the surface area. Or at least the ones I have run. I have around 20-30 lbs of these pins currently, I'll take a picture and post for comparison.

If it's the same pins and they are partly silver, you want to digest in Nitric first so the silver goes into solution as silver nitrate. If you process with HCl first, you will get silver chloride which is more difficult to reduce later. Also if you start with HCl, it will form a protective layer on the pins and prevent the HCl from attacking the rest of the pins. It also creates a huge mess. :mrgreen:

I start off incinerating first, it always seems that there is a lot of other material mixed in with the pins, bits of plastic, etc. Then I soak them with Nitric. You have to be patient, if there is a lot of silver it will take some time to dissolve. Then do your normal wash + incineration and proceed as you would normally.