Do I have the holey grail of 90% Iridium or possible arsenic

[SilverLiningSteve]

I recently won this item in auction. After speaking with the seller we decided to hold payment pending University analysis as I will be into it for just under 11k. As you can see in the photos the reading from multiple XRF attempts return 90% Iridium 8.6% Platinum 1.4% Lead. As you can see it is misshapen the measurements listed are 2.1in.by 1.25in.by1.35 it weighs 435.1 grams. It is misshapen but still the density seems too light for the composition reading to be accurate. This is one of two chunks roughly same weight and size the other both registering the same composition I only won one of the chunks, the other went over 15k. After much research I'm skeptical of the of the possibility these reading are accurate . Just this reading seems so firm as it only reads 3 metals and when I read the description of pure Iridium its checks all the boxes. Any help on this would be appreciated and I will be sure to follow up with details .

 

[g_axelsson]

Looks like massive arsenic to me, and it's too light too as you have noted.

Göran

 

[Ultrax]

The most primitive way is to heat a finely ground sample in a closed test tube at an angle - arsenic compounds are volatile, so a white oxide and a black coating of metallic arsenic quickly form on the cold part of the test tube.

Or send the sample to a certified lab to make a Marsh test for arsenic.

 

[Yggdrasil]

I recently won this item in auction. After speaking with the seller we decided to hold payment pending University analysis as I will be into it for just under 11k. As you can see in the photos the reading from multiple XRF attempts return 90% Iridium 8.6% Platinum 1.4% Lead. As you can see it is misshapen the measurements listed are 2.1in.by 1.25in.by1.35 it weighs 435.1 grams. It is misshapen but still the density seems too light for the composition reading to be accurate. This is one of two chunks roughly same weight and size the other both registering the same composition I only won one of the chunks, the other went over 15k. After much research I'm skeptical of the of the possibility these reading are accurate . Just this reading seems so firm as it only reads 3 metals and when I read the description of pure Iridium its checks all the boxes. Any help on this would be appreciated and I will be sure to follow up with details .

Search the net for Arsenic and you will find pictures very close to what you have.
If Iridium it would be close to 1,3 Kg and if Arsenic close to 440g just as a quick calculation.
So it is safe to assume it is not Iridium.

 

[SilverLiningSteve]

Looks like massive arsenic to me, and it's too light too as you have noted.

Göran

Turned out to be bismuth

 

[SilverLiningSteve]

Search the net for Arsenic and you will find pictures very close to what you have.
If Iridium it would be close to 1,3 Kg and if Arsenic close to 440g just as a quick calculation.
So it is safe to assume it is not Iridium.

It turned out to be 100% bismuth

 

[g_axelsson]

Turned out to be bismuth

That's very interesting, I have learned something new today. Seems like we have two elements that looks like iridium to an XRF, not only arsenic.

As a side note, bismuth and arsenic is really close in the periodic system and both are part of group 15.

Göran

 

[Golddigger76]

Good thing you didn't win the other piece too that sold for 15k !!!

So do you have to pay 12 grand for it or have you already paid for it ?

I thought the crystalline structure looked familiar and doing a search on Google images there's plenty of examples that are very similar to the sample in your pictures.

 

[SilverLiningSteve]

Good thing you didn't win the other piece too that sold for 15k !!!

So do you have to pay 12 grand for it or have you already paid for it ?

I thought the crystalline structure looked familiar and doing a search on Google images there's plenty of examples that are very similar to the sample in your pictures.

The sale was contingent on the results of the test I didn't pay a thing. I google lens it prior to the auction and saw bismuth and other ingot that looked similar but wishful thinking and dreams of a nice vacation takes over in auctions