Jin Heyin won't rust normally, because their chemistry is too dead,basically be, scarcely with other element chemical combination, although heat 1000 degrees of above, still won't close with oxidation, alleged " a person of integrity can stand severe tests " .
However, gold, silver is not won't rust absolutely. In aqua regia, gold is met by rustily. Aqua regia is the strongest acid, it is a nitric acid and 3 hydrochloric acid (calculate by volumenometer) mixture. It can learn reaction with fair biochemistry, make gold turns solubility into compound.
Silver should compare gold some more lively, not only it is aqua regia can rustily it, sulfureous also can make it rusty, the vulcanization that becomes black is silver-colored. Shining silver is used sulfureous brush, meet nigrescent. because such, the surface of archaic silver often nigrescent, and archaic gold vessel sparkles as before shine. If you use ammonia water to swab silver, so nigrescent surface is met very fast brighten, look brand-new. Because vulcanization silver and ammonia water react,this is, turned Yi Rong into the content of silver-colored ammonia complexing at water. Same argument, bronze ware is nigrescent also can polish with ammonia water. Accordingly, somebody calls ammonia water " the water that brush copper " .
