I’ve looked through the archives but I still have some questions I
hope you all can answer.
I have some unmarked vintage jewelry that I believe is gold and want
to test for the karat content before selling. (I tried taking them to
a local pawn shop for testing, but they didn’t offer those service.
I don’t want to search all over creation to find someone who will do
this for me and I know in the long run, learning how to do it myself
will save me a little money.)
I know a little about acid test kits, but if I’m going to invest in
one, need the easiest one to use. Something with clear instructions,
Are test kits fairly reliable?
What kind of “damage” can I expect in the test area (even after
neutralizing it with baking soda)?
Will I still be able to tell what karat of gold I have on some
pieces if they turn out to be rolled gold, gold filled, rose gold or
gold plated items?
Any health concerns with the chemicals or is outdoor ventilation
Thanks in advance,
I have very limited experience with gold testers, but here’s what I
We have an old (circa 1975) G-1 tester. You attach a metal clip to
the jewelry, then touch the end of a electrically conductive
goop-containing tube to the jewelry, press a button and it comes out
with a number you compare to a chart with ranges for different
metals. In theory, the tester can test platinum, up to 18 karat gold,
and plated/filled materials. It sometimes leaves a round tarnish mark
~ 3 mm in diameter that polishes off easily with rouge. The test
results seem reliable and accurate when the device works. The problem
is getting the “goop” to come out of the tube correctly (it dries up,
it moves up the tube instead of down, it goes out the bottom but
doesn’t touch the higher contact point, etc.). I have wasted many
hours and many tubes of goop trying to get a reading. Of course, my
machine is old, and we only use it every couple of weeks.
I have looked at other tube-based systems, and they seem very
similar to the one we have. There are also electronic systems that
work similarly, except you put the jewelry and goop into a well. I
was told those are not as accurate, but don’t have any personal
experience with them. We have a small, enclosed store without enough
ventilation for the traditional acid method. Last year at the Rio
show in Tucson I spoke to the rep for Presidium. According to him,
Presidium is developing a metal tester that should be easier to use
and even more accurate through platings etc. Their new tester was not
available as of this year’s Rio show, but they told me it may be
ready in six months. I plan on buying one as soon as it becomes
I hope this helps you, and that you’re doing some great Valentine
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