Treatment of a Silver Dragon for the Removal of Silver Cyanide and Chalconatronite
01 Jan 1986-Journal of The American Institute for Conservation (Routledge)-Vol. 25, Iss: 2, pp 73-81
TL;DR: In this article, the corrosion products on a silver dragon suspected to have been treated with cyanide revealed both silver cyanide and chalconatronite, which can be formed on silver objects cleaned or replated using a cyanide solution.
Abstract: Analysis of the corrosion products on a silver dragon suspected to have been treated with cyanide revealed both silver cyanide and chalconatronite. It appears that both of these corrosion products can be formed on silver objects cleaned or replated using a cyanide solution. These corrosion products darken with exposure to light; therefore, they may be mistaken for silver sulfide. In order to determine how to remove the highly poisonous cyanide corrosion product, numerous tests were run. Using a carefully timed procedure the silver cyanide was removed with an aqueous solution of 20% sodium thiosulfate. The chalconatronite was removed mechanically.
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TL;DR: In this article, the authors present a range of possibilities to assist the conservator in defining the state of conservation and the possible need for treatment and protection of an object, with special emphasis on tarnishing and mineralization.
Abstract: The present article aims to offer a comprehensive approach to the conservation of silver objects. It is not intended to suggest or recommend any specific recipe or treatment for a given case. Instead, the paper presents a range of possibilities to assist the conservator in defining the state of conservation and the possible need for treatment and protection of an object. Besides giving the background to the structural properties of alloys used in silver artefacts, the possible forms of silver deterioration are presented, with special emphasis on tarnishing and mineralization. Less frequent cases, such as selective, localized and stress corrosion are also discussed. A descriptive review of materials and methods used for cleaning, consolidating and protecting silver artefacts follows, accompanied by an extensive bibliography.
53 citations
TL;DR: In this article, the mineralogical changes which occur during the reaction of copper(II) chloride with carbonate in aqueous solution have been investigated, and compared with those involving copper(I) chloride, nantokite, CuCI, and copper artifacts coated with malachite, CU2CO3(OH)2
Abstract: Mineralogical changes which occur during the reaction of copper(II) chloride with carbonate in aqueous solution have been investigated, and compared with those involving copper(I) chloride, nantokite, CuCI, and copper artifacts coated with malachite, CU2CO3(OH)2 The reactions observed and the products obtained are seen to have implications with respect to the use of aqueous sodium carbonate solutions to stabilize archaeological copper objects. The frequent observation of the mineralogically rare species chalconatronite, Na2Cu(CO3)2·3H2O, on the surface of treated objects is readily explained by known reaction chemistry. Its formation can be minimized by washing the object after treatment.
31 citations
TL;DR: In this paper, a new pale blue corrosion product has been found on copper alloy artifacts in the collections of a number of institutions, and the corrosion product is a copper(II) compound, containing copper and sodium in a ratio of approximately 1:1.
Abstract: A new pale blue corrosion product has been found on copper alloy artifacts in the collections of a number of institutions. The corrosion product has been characterized using X-ray powder diffraction, X-ray photoelectron spectroscopy, wavelength X-ray dispersive spectroscopy and Raman microspectroscopy. The corrosion product is a copper(II) compound, containing copper and sodium in a ratio of approximately 1:1 along with formate and acetate groups. It is speculated that formic (methanoic) and acetic (ethanoic) acid vapors arising from materials used to house the objects contribute to the formation of this compound.
26 citations
TL;DR: A specific tarnishing pattern was first observed in 1992 in a large collection of daguerreotypes viewed under short-wave ultraviolet illumination as mentioned in this paper, a straightforward examination and documentation technique available to conservators.
Abstract: A specific tarnishing pattern was first observed in 1992 in a large collection of daguerreotypes viewed under short-wave ultraviolet illumination. While daguerreotypes have been closely inspected under visible light, there appears to be no report of the use of short-wave ultraviolet illumination, a straightforward examination and documentation technique available to conservators. The scope of this investigation includes preliminary analysis, characterization of the tarnish, and a study of its rate of occurrence on a group of 110 daguerreotype plates. Two methods of instrumental surface analysis were used in this study: scanning electron microscopy and Fourier transform infrared analysis. These useful, nondestructive analytical methods are available to the conservator for examination and documentation and provide both inorganic and organic data. The findings indicate that the presence of this fluorescing tarnish may provide evidence of specific past treatments applied to daguerreotype plates. The f...
11 citations
01 Jan 2014
TL;DR: Yemen's earliest history, dating from the stone and bronze ages, has only recently been studied as mentioned in this paper, and the period of the first three orthodox caliphs was one of stability and steady growth of Islam in Yemen, with the assumption of the caliphate by Ali ibn Abi-Talib in 656 A.D (35 A.H).
Abstract: Yemen's earliest history, dating from the stone and bronze ages, has only recently been studied. Islam came to Yemen during the time of prophet Mohamed. The period of the first three orthodox caliphs was one of stability and steady growth of Islam in the Yemen, with the assumption of the caliphate by Ali ibn Abi-Talib in 656 A.D (35 A.H). A civil war broke out between his followers and those of Muawiyah, and Sana'a adhered to the Ali side. Muawiyah had to conquer Sana'a by force in order to establish Umayyad authority there. From there after Sana'a continued to be ruled by governors appointed by the caliph, first Umayyad (41- 132 A.H) and then, after transfer of the caliphate to Baghdad, Abbasid.
1 citations
References
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Book•
19 Mar 1998
TL;DR: Encyclopedia of Chemical Technology The Third Edition of the Encycled encyclopedia of chemical technology as mentioned in this paper is built on the solid foundation of the previous editions of the encyclopedia, which has been updated and updated and many new subjects have been added to reflect changes in chemical technology through the 1970s.
Abstract: Encyclopedia of Chemical Technology The Third Edition of the Encyclopedia of Chemical Technology is built on the solid foundation of the previous editions All of the articles have been rewritten and updated and many new subjects have been added to reflect changes in chemical technology through the 1970s The new edition, however, will be familiar to users of the earlier editions comprehensive, authoritative, accessible, lucid The Encyclopedia remains an indispensable information source for all producers and users of chemical products and materials In the Third Edition, emphasis is given to major present-day topics of concern to all chemists, scientists, and engineers--energy, health, safety, toxicology, and new materials New subjects have been added, especially those related to polymer and plastics technology, fuels and energy, inorganic and solid-state chemistry, composite materials, coating, fermentation and enzymes, pharmaceuticals, surfactant technology, fibers and textiles New features include the use of SI units as well as English units, Chemical Abstracts Service's Registry Numbers, and complete indexing based on automated retrieval from a machine-readable composition system Once again this classic serves as an unrivaled library of information for the chemical and allied industries Some comments about Kirk-Othmer-- The First Edition "No reference library worthy of the name will be without this series It is simply a must for the chemist and chemical engineer" --Chemical and Engineering News The Second Edition "A necessity for any technical library" --Choice
3,513 citations
Book•
01 Jan 1956
TL;DR: Inorganic spot test analysis has been extensively studied in the literature, see as discussed by the authors for a survey of the current state and prospects of inorganic inorganic spot-test analysis, including preliminary orientational tests for the elements, their ions and compounds.
Abstract: Development, present state and prospects of inorganic spot test analysis. Methodology of spot test analysis (completely revised and enlarged by Dr. G. Skalos). Preliminary orientational tests. Tests for the elements, their ions and compounds. Application of spot reactions in tests of purity, examination of technical materials, studies of minerals. Tabular summary.
1,663 citations
TL;DR: Spot Tests in Organic AnalysisBy Prof. Fritz Feigl.
Abstract: Spot Tests in Organic Analysis By Prof. Fritz Feigl. Sixth, enlarged and revised English edition. Translated by Prof. Ralph E. Oesper. Pp. xx + 675. (Amsterdam: Elsevier Publishing Company; London: D. Van Nostrand Company, Ltd., 1960.) 65s.
493 citations