Q: I got a gold testing kit, but I used up all the little tubes of gel it came with. Can this magic goop be purchased in bulk so I can do away with those nasty tubes? What is your solution?
A: My solution was to discard the relatively useless tester. Without the gel, it’s useless, and mine was one of the first models, much less convenient to use than current ones, with a reading that was just a number you had to then compare with a chart. I went back to using traditional test acids. A small bottle of nitric, and another of hydrochloric. I feel in the amounts one is using for gold-testing they’re safe enough, and their shelf life (not unlimited, by the way) is a whole lot longer than those silly gels.
With practice in the testing method, I feel the accuracy one can get is about the same too. It does, however, take some practice. The premixed acids, already calibrated for certain karats, are easier to use, but I feel they are potentially less accurate in some situations. I prefer an actual comparison test on a streak of the unknown with a streak of a known test piece of metal. Add some Schwerters salts mix for testing silver, and a bit of table salt for some tests, which makes a very weak chloride source when added to nitric, that’s slower-acting than what you’d get from adding HCl to the nitric acid.
by Peter W. Rowe M.F.A., G.G.