Question about acid testing gold

It is only marked PAT and copyright. Other marks are too faint to make out. The diamonds are small but real. When I did the acid testing it held at 14k but turned a little brownish or copper looking. it did not test as any type of silver or gold with 18k. I read somewhere the browning could be either other metals mixed in or the fact that the it gold is less than what I tested it for. There is so much out there and I do t want to follow the wrong lead. What would you say the it is?

thanks for any advice.

 

A scrapper once told me to let the acid sit on the scraping for at least 15 minutes, if it is 14k then the scraping will hold that long. If lesser or gold filled it will gradually fade.

Did you try 10k acid? Do you get the same brownish or coppery color?

 

I let it sit very long but probably not 15 minutes. I’ll try that and ten and then get back here. Ty @Marie Forjan

 

Top circles are 10k acid. Bottom 14k. On the left I tested another gold, unmarked piece which is Victorian or so In age and the 18k made it go bright blue. The 10k on that one did not hold. Is it vermeil maybe?

the gold testing is on two rings. Ring one has the 4 circles because it looks like it was sized and I wanted to be sure they didn’t mix metals. Ring two is to the right.
What do you think? I can safely say they are 10k but the 14k does not budge it, it only darkens it Ring one on the other portion I tested didn’t even darken either. I hope this makes sense. Lol

@Marie Forjan Thank you for helping

 

What is on these 2 areas? Solder,crack?

 

poor picture taking on my part? @Hollyblue ty

 

Any help with the testing, please?

 

The 10k solution holds, but the 14k diminishes your streak a little.
So maybe the ring is 12k.

If you make longer streaks on the stone, then you can place the drops of acid further apart and the drops wont bleed together.
Then your results will be easier to decipher.

Also, between rounds of testings, wipe the stone clean with a wet paper towel.
That way successive tests will always be on a clean stone.

 

Hi!
I clean in between with 409. My father taught me to use it to neutralize the acid. He used it so he wouldn’t constantly burn himself with the acid. Is the 409 good enough to clean in between?

im so afraid of damaging the items by scratching them too much.

 

I don't know if 409 makes any difference. I have always used a wet paper towel to clean the stone. It's been working for me all these years!

If you make a long streak, like maybe 1"x 1/16", then you can neatly place all the drops along that one streak. Starting with 10k on one end and working your way up to 22 if necessary. So one streak will be all you need to test one item, and you wont need to keep rubbing your item on the stone.
Rub lightly, just enough to create the mark. Don't be heavy handed.
You just need a light touch, not enough to put an obvious flat area on your item.

I have some pieces in my collection that I have already tested. I need the loupe to see where I rubbed it on the stone. You should only see a tiny flat spot on a previously tested piece.

I also use a small pen light to view my results. A bright light right on your stone helps to see very clearly the change under the drop of acid. And I mean ONE drop. I wont make a big puddle.
I am very stingy about using up my acid! LOL

The photo below shows the results of a 14k ring. The mark I made is roughly 1"x1/16".
The 10k drop is on the bottom, followed by 14k, 18k, and 22k.
As you can see, the mark held at 10 and 14, but vanished under 18.
(I didn't really need the 22k drop, but I just wanted to show you how the drops can be placed on the streak without bleeding into each other.)
So we know this ring is 14k.

I held my pen light over the stone so you can see how the light really amplifies the streak under the drop of acid.
Because I did it this way, I don't need to make any more marks.
I got my 14k result, and the ring is unharmed!

 

Ok, so I see the 14k changed the mark in color slightly, right? That was my reservation with what I tested. There was a color change but the mark stayed, even after a lot of time
Thank you for taking the time to help me

 

just wanted to say 'thank-you' stracci for you excellent description with a photo, if I was testing stuff it would certainly help

 

Thanks @cxgirl
I am happy to help! Using the acid kit can be a bit confusing.
I tried to be clear about the process.
It is so nice to test your own jewelry finds at home, and be sure of the metal content.