Questions about testing for gold using a stone and acid

Alright, I tried to test a gold ring I dug with a friends brand new testing kit a couple weeks ago and we scratched the ring on the stone pretty dang hard. Now once the acid was applied, a lot of the gold particles started floating around in the small puddle of acid, but they stayed there and still looked like little gold particles. When using the 10K acid, no reaction at all, when using the 14k a little bit of smoky fumes but the gold just floated around same as the 10K, with the 18K solution is was annihilated...

So seeing the smoky fumes at first with the 14K, I figured it must have been a 10K ring. But even then the 10K lifted the gold off the stone..

I then took it to my friends pawn shop and he tested it by putting acid right on the ring and he determined it to be a 14K ring...

Thinking back, I am figuring that the smoky fumes at first with the 14K and 18K were because of something that was already on the brand new stone before the gold was even scratched.

And the fact that even the 10K and 14K lifted most of the gold off the stone but did not dissolve the gold was because of the nature of the stone or something that was on the stone before the scratch test.

Does the above make sense to you guys?

And the scratch of gold particles floating around in the pool of acid is not the same thing as the scratch dissolving?

Also I understand if you intend on not using a stone a just testing on the piece itself, you still need to file or grind part of it to make sure you are not just testing the plating..

Looking forward to your thoughts on this..

Thanks guys!!

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