Gold Inconsistent with Acid...?

Hi all! Either I'm not adept at reading acid (most likely this) or its being wonky.

Things keep testing as possible gold and then the next day not so much. What does it mean when the acid makes the scratching not yellow but not gone completely? Like I'm getting a lot of dark lines left...shouldn't it all evaporate if its not gold?

I try to do it enough that I get through any plating, and then go back to the piece examine the area for any color changes.

Also I find it suspicious its finding gold sometimes on items that aren't marked...

The acid is less than 6 months old, and not used often, kept in a dark drawer.

Here's the items in question. The ring in particular is annoying because its marked 18k and the acid refuses to cooperate lol. The chain and tie pin aren't marked, and show up with dark streaks after the yellow evaporates (which takes 4 '1-1thousands') on 9k.


The ring: Doesn't seem to be the best quality. Marked both 18k and 750, the hallmarks look legit in their shape but itsn't it odd to have both marked? No other marks. There's a couple of nicks and scratches, all of which show the same color underneath. The acid evaporates immediately at 18k, and even 9k. Just dark spots. The 9k still works on my 14k chain soooo? It seems odd to not even be plated, what's going on here?



Left: 9k. Right: 18k.

I'll post the locket in a minute, just realized I didn't take more photos of it.​

 

That the gold is a lower carat than you're testing for.

Depends on the metal.

Not marked can still be gold, a lot of gold isn't marked. Here in Europe German gold is rarely marked, but some others too.

 

It may not be gold, at least not the caratage it is marked for.

The Germans call that "Autobahngold", fake gold sold along the Autobahn, the German highways. It is often made in Turkey, but some other countries have similar fakes.

If your testing acid works well with items you know to be gold, absolutely certain, than this ring is probably Autobahngold.
Maybe have it tested by a jeweller?

 

How common is lower than 9k? It seems a lot of the pieces I test are less than 9 and it gives me a feeling I'm reading it wrong. Its the same with the marked, how do I happen to find all the unmarked stuff? Seems off haha

I probably should get it tested, but the 18k seemed adamant it wasn't gold at all. I might keep it by for a jeweler to look at, as its quite heavy.

 

The locket I'm more certain of, but again its a lower carat than 9. Its marked, but the mark is impossible to read. Its rather well made too. It had the remnants of old paper inside.



The acid stayed bright at first, and then faded to a dark mark in 3 seconds.
​

 

Lovely locket, Rachel.

That probably means it is slightly under the caratage you tested for.
What do you use to test it on?

 

Thank you! I just used the test stone the kit came with. This is the only piece the test has been consistent on...

 

Ahhh the ever lasting testing difficulties.
I feel your pain. I often have the same issues you are describing here.
Sometimes something will test as 14 carat and a few weeks later...not!
I keep my 'maybe' items all cataloged and I keep them together to be tested by someone else, someday.
I never sell something I am not 100% sure about though.
For now, I just settle with 'I m not sure but it looks promising'
Also, being a collector of shiny things, for me its not always so important to exactly know the material.
Knowing the history is sometimes much more fulfilling. At least to me.

 

If the ring is supposed to be 18k, I would test it with 14k acid. Nothing should happen to the scratch. It shouldn't change color. From my experience, the scratch shouldn't change unless you test it with 22k gold acid.

 

I tested it with 9k and that also seemed to disappear fairly quickly!

I found a high end jeweler in the city that specializes in antique gold, so I may grab some of the question marks and head that way! I'll have to contact them. I don't really know who else to look for in terms of jewellers. I have an image in my head of an older man in the back of a dark shop of treasures with his tools and a lamp I know pretty much for a fact we don't have one of those locally. At least they don't come up online.

 

You might be surprised, and find one!

 

That'd be nice!!