Tricky issue please help

[Devildog]

Hello all,
I have another brain buster here. First time I've had this issue with gold.
I inquarted some 14k with silver. About 4 grams of 14k. I did the refine using distilled water with Nitric. Dissolved down to 1.6 grams. This button now will not, dissolve any further. I've tried a fresh batch of distilled and nitric. Sat on heat for 3 hours and did nothing. Put it in a small batch of Aqua Regia, fizzled a little. Down to 1.3g to 1.4g depending on how the scale feels that moment , then it quit again.
I melt the button again just to see if maybe some excess borax was present. Had a nice gold metallic color during the melt, as soon as I quenched it in cool distilled water, it coated to a dark gray color with some gold showing through it.
I tested this with XRF gun and it tests at about 9k. But my question is, what is happening as to why it won't dissolve any further?
Below is a photo after the last quench. Maybe it's contaminated by something on my melt dish?
I do have one dish for Gold, one for Silver, and one for the unknowns.
Again, as always I am extremely grateful to the men and women of this forum, for always educating me and helping me understand, just what could be happening, as well as, sharing your amazing knowledge that I wish I had a 10th of what you all possess.
Thank you in advance for your aid in this matter.
CHEERS MY FRIENDS!!!

 

[Shark]

Is it possible that a piece was not karat gold? I am sure you know but 4 grams of 14K should produce about 2.3 grams of pure gold.

 

[Martijn]

Did you inquart it to 6K and made it a homogenous alloy by stirring?
Was the 14K gold yellow or white? i.e, was there platinum in it? This could keep it from dissolving in cold AR.

It sounds like your scale is off, it needs new batteries, calibration or replacement. To measure grams and calculate karat, you need better precision i think.

14K has a tolerance, some go under it. some are just plated or gold filled. So combined with your scale the 1.6 may still be in the correct range with the "about 4 grams of 14K"

Was the 14K clean gold alloy or with stones or springs or something else?

it coated to a dark gray color with some gold showing through it.

That sounds like something that won't alloy with gold is in there.

 

[tmj883]

How much silver did you add to inquart your gold? And how did you prepare your alloy from inquartation for parting in nitric acid?