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 Our gold testing kit accurately tests 10K, 14K, 18K, 22K, and 24K gold, as well as silver and , preventing purchasing or recycling gold tester kit Includes 10g solutions and a test stone, for safe testing that 't damage your jewelry, and authenticity 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 Simple, easy-to-follow process requiring no expertise, the gold tester ideal for individuals to quickly test jewelry, gold bars, or collectibles, Weight: 0.18518830008 Pounds, Manufacturer: Hipzeepo