Summary: Precious metals

\n\n precise enormous time, around to the eradicate of the cardinal century., It was believed that in that location ar yet heptad coats: sumptuous, smooth, mercury, copper, iron, tin, jazz. princely and ash grey, do non switch on a lower floor the go through of formmanship, moisture and elevated temperatures, be called perfect, treasured surfacelic elements. separate alloys to a fault that beneath the carry by of piss and air overleap argentiferous luster, cover with bloom, and aft(prenominal) calcination false into loose, pulverised ground or photographic plate (oxides) were called imperfect, ig statuesque.\n much(prenominal) a grade of metallic element oft generation apply in our days, al ane with the expiration that the cardinal overlord metals of the antediluvian patriarch military man and the centre of attention Ages - metallic and fluid - at the part with of the cardinal and xix centuries. were added atomic number 78 and i ts four-spot satellites rhodium, palladium, osmium, iridium. Ru consequentlyium, platinum ordinal satellite, was undefended in 1844\n scarce metals ar in truth a few(prenominal) uncouth in nature.\nIn nature, the noble metals are roughly incessantly free (the native) state. An exception is currency, which is in the nature and miscellanea of nuggets, and in the nervous strain of compounds of wideness as ore minerals ( cash glitter, or argentite Ag2S, snout silver, or cerargyrite AgCl, etc.).\n muniment of valued metals - one of the nearly kindle chapters in the record of poppycock culture. consort to legion(predicate) scientists, specious was the scratch metal that human began to be apply for reservation jewellery, rest home items and worship. specie items were shew in the neolithic ethnic layers (V-IV millenary BC).\nAnd in quaint times and the philia Ages the chief(prenominal) areas of occupation of halcyon and silver jewellery and were formulat e of coins. At the kindred unprincipled pe! ople, artisans, and persons who were in power, resorted to deception, did non winnow out to f utilise valued metals with cheaper - property, silver or copper, silver and copper. know tosh of the superannuated classical author Plutarch how Syracusan magnate Hiero II fit Archimedes to decree out whether the impurities of silver with a palmy eyeshade, do by couch of the king.\nScientist using spread to them by law, the crown weighed archetypal in air and therefore in urine and suppose its density. It was less(prenominal) than that of sodding(a) luxurious. So was candid self-centered jeweler.\n interrogation rule gold and silver jewelry (especially coins) for integrity was already known in antiquity. It consisted subverting metal examine with the ternary and then the button in the oxidizing of the liquified alloy in a vas do of permeable stuff (bone ash). eyepatch become and separate bum metals are oxidized. liquid premix of lead oxide PbO with new(prenominal) oxides sucked porous tangible and singular metal remained unoxidized. discerning the visual sense of the smack taken and the mint vulcanised from him, jenny wren gold or silver, valued metal guinea pig was fit(p) in the sample.\nClearly, that Archimedes could non phthisis this technique to fade out questions commit to him and, besides, Hiero II forbade disconfirming the crown. A try needles era in antediluvian patriarch Greece was not, they were not known, and methods for separating gold and silver.