{"id":2832,"date":"2015-05-22T20:45:45","date_gmt":"2015-05-22T20:45:45","guid":{"rendered":"http:\/\/cool.conservation-us.org\/cool\/osg\/?page_id=2832"},"modified":"2020-04-20T20:31:52","modified_gmt":"2020-04-20T20:31:52","slug":"oconnor","status":"publish","type":"page","link":"https:\/\/resources.culturalheritage.org\/osg-postprints\/v22\/oconnor\/","title":{"rendered":"Silver or gold? Surprising challenges in cleaning a 19th-century Persian water pipe"},"content":{"rendered":"<p><em>Ariel O\u2019Connor, Meg Craft, Glenn Gates, and Julie Lauffenburger<\/em><\/p>\n<h4>Abstract<\/h4>\n<p>A heavily tarnished 19th-century Persian water pipe, or nargile , made of gilded silver decorated with gemstones required cleaning for exhibition at the Walters Art Museum. X-ray fluorescence spectrographic analysis indicated an alloy of silver with copper, gold, and lead. Standard methods for mechanical tarnish reduction were tested, but all produced a silver-colored surface. Further x-ray fluorescence spectrographic analysis revealed that even the gentlest mechanical method\u2014solvent cleaning with a cosmetic sponge\u2014removed gold from the surface. Chemical test cleaning with acidified thiourea, or \u201csilver dip,\u201d removed tarnish and preserved gold, but research has shown problems with this method, including potential leaching of copper, microetching, residual surface complexes, and increased light reactivity. Pros and cons of each method were considered, and thiourea was selected as least harmful. Methods for the safe use of thiourea in this context are discussed, and a new approach with non-woven cotton pads is introduced for cleaning.<\/p>\n<p><a href=\"http:\/\/resources.culturalheritage.org\/osg-postprints\/wp-content\/uploads\/sites\/8\/2015\/05\/osg022-10.pdf\" target=\"_blank\" rel=\"noopener noreferrer\">Download full article<\/a><\/p>\n\n\n<h6 class=\"wp-block-heading\"><a href=\"http:\/\/resources.culturalheritage.org\/osg-postprints\/postprints\/v22\/\">2015 | Miami | Volume 22<\/a><\/h6>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Ariel O\u2019Connor, Meg Craft, Glenn Gates, and Julie Lauffenburger Abstract A heavily tarnished 19th-century Persian water pipe, or nargile , made of gilded silver decorated with gemstones required cleaning for exhibition at the Walters Art Museum. X-ray fluorescence spectrographic analysis indicated an alloy of silver with copper, gold, and lead. Standard methods for mechanical tarnish [&hellip;]<\/p>\n","protected":false},"author":16,"featured_media":0,"parent":2802,"menu_order":10,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-2832","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/resources.culturalheritage.org\/osg-postprints\/wp-json\/wp\/v2\/pages\/2832","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/resources.culturalheritage.org\/osg-postprints\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/resources.culturalheritage.org\/osg-postprints\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/resources.culturalheritage.org\/osg-postprints\/wp-json\/wp\/v2\/users\/16"}],"replies":[{"embeddable":true,"href":"https:\/\/resources.culturalheritage.org\/osg-postprints\/wp-json\/wp\/v2\/comments?post=2832"}],"version-history":[{"count":0,"href":"https:\/\/resources.culturalheritage.org\/osg-postprints\/wp-json\/wp\/v2\/pages\/2832\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/resources.culturalheritage.org\/osg-postprints\/wp-json\/wp\/v2\/pages\/2802"}],"wp:attachment":[{"href":"https:\/\/resources.culturalheritage.org\/osg-postprints\/wp-json\/wp\/v2\/media?parent=2832"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}