First time here using acid testing for gold. So just wanna share my results and see what opinion you guys have.
Im recycling an old bracelet with the letters"HKH" Stamped on it, which should stand for an old danish goldsmith Henning Kaj Hansen. I see other vintage bracelets from same goldsmith wihch are most commonly sold online as 14 karat, so im pretty sure it’s legit, however no stamp number.
I put it up against my own sprue buttom where i know i’ve got exactly 14 karat gold in.
How do you read the results? 18 karat disolved both within 20 sec… When the acid drops for 8 & 14 karat were still there on both samples, they dident seem to dissolve. Only difference were that the Braclelet sample turned a bit redish and not as clear as my own gold sample.
From here I would say both were 14 karat gold, but then i washed the stone brick, blank spots were showing on all Karats on the bracelet, but not my own sample…
Perhaps i shouldent think too much about how it looks after i rinse, but only if it dissolves when the acid os on the stone?
And while we’re at it, other effecient ways to test this beside 15.000 $ + metal “gun” reading devices ?
With the SG of 14 kt yellow being 13.07 and that of sterling silver being 10.36, you could easily do an SG measurement. Don’t bother with the sophisticated shelf over a scale, just weigh the chain suspended in water and then lying down on the bottom of the tared container with water in it. A simple way to get a rough SG. You can use light fishing line to secure the chain into a ball and suspend it, if needed. -royjohn
Keep it simple, I start with 2 long scratches, one is known 14K and the unknown, test with 14K acid on one end of the scratch. if one discolors (fairly quickly, say 5-10 seconds) I know it is less than my known mark. It can be complicated to distinguish 9k from 10K, but the 9K will darken a little more than the 10k.
Total testing time is in the seconds.
Be sure the scratch marks are done with roughly the same force, also be sure you get through the top surface in case the piece is gold-filled or heavily plated.
Judging from your first picture I would say the bracelet is below 14K.
I have been buying gold for 40 years now, and I only use 14k, 18K, platinum acid and straight 70% nitric acid. the 70% gives me a yes or no test, (silver and gold) and normally the platinum acid is used to clean the scratch stone.
