If you draw gold on the touchstone and drop the solutions, the real gold remain on the touchstone while the fake gold be dissolved or oxidized to a cyan Our gold testing kit accurately tests 10K, 14K, 18K, 22K, and 24K gold, as well as silver and , preventing purchasing or recycling Featuring fine, smooth and extremely hard, with a hardness of nearly 7.0. When it is scratched on a stone, no sound can be heard. If the touchstone is cyan, it indicates that the gold contains a relatively high amount of silver gold tester kit Includes 10g solutions and a test stone, for safe testing that 't damage your jewelry, and authenticity Simple, easy-to-follow process requiring no expertise, the gold tester ideal for individuals to quickly test jewelry, gold bars, or collectibles, Weight: 0.4188782978 pounds, Manufacturer: Kueohse