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V25 2022 INDEX E-SYLUM ARCHIVE VOCABULARY TERM: HORN SILVERHere's a short but interesting entry from Dick Johnson's Encyclopedia of Coin and Medal Terminology. -Editor Horn Silver. A type of tarnish, silver chloride, formed on the surface of silver exposed to hydrogen chloride. Characteristically horn silver is a white to pale-yellow or gray color and in natural state is cerargyrite (AgCl). Removing a tough tarnish like horn silver is difficult, as no chemicals can dissolve it. Extensive horn silver needs to be removed physically, the best is by reverse electroplating. Such reverse plating, however, removes not only the tarnish but also the top layer of silver. Physical removal can also be accomplished by sandblast or abrasive blast, or by light pickling with sulfuric acid. Needless to say, it should only be done by a professional. Until reading this I'd never heard of either Horn Silver or reverse electroplating. Interesting way to clean a coin or medal, and certainly something that should only be tried by a professional. Is anyone aware of this being practiced today, perhaps at a museum or one of the grading house conservation services? As for Horn Silver, the Hudson Institute of Mineralogy says the name came about as follows: "This superficial silver ore is polished by desert wind and dust to the dull luster of a cow horn, hence the name "horn silver"." -Editor
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Wayne Homren, Editor The Numismatic Bibliomania Society is a non-profit organization promoting numismatic literature. See our web site at coinbooks.org. To submit items for publication in The E-Sylum, write to the Editor at this address: whomren@gmail.com To subscribe go to: https://my.binhost.com/lists/listinfo/esylum All Rights Reserved. NBS Home Page Contact the NBS webmaster 
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