Hi Kyle, there is no H2S type smell (rotten eggs) smell when hydrochloric acid is put on these samples. I've attached the golden looking mineral on slate image, that is resistant to aqua regia soluton from JSP, and the platinum solution from JSP.  As one can see, there are crystals within this matrix of golden material, some of which are covered by the golden material, but we also have cases where a blue, or white crystal, hexagonal in habit, is seen, where an area has been left relatively clean of the golden material. 

 We have tried to scatch some of the crystals with a high carbon knife, which has hurt the knife, but not hurt the crystals at all that were found in a quartzite matrix. 

In the case of slates, I am able to scrap off the crystals onto a scratch pad, as the matrix material (slate) is so soft underneath the crystals.

I've attached what the local university provided for XRF analysis below. As we can see, gold isn't really showing up much with this XRF analysis (it is minor gold).  

Au          0.197

Fe           15624

Cu           5.264

Pb           1.707

 JJC-3

Au          0.356

Fe           7336

Cu           1.0

Pb           2.250

 

JJC-4

Au          0.063

Fe           6687

Cu           0.793

Pb           1.554

 

 

But that is all speculation. You should confirm with the analyst what happened, or at least what is being measured here.

Kyle

The SEM analysis reveals the matrix is "golden mica."  However, the crystals aren't explained yet by the academic, or anyone.  Apparently mica survives aqua regia quite well, according to the academic.