Impurity Elements in a Lead Seals and Stamps of Middle Ages and Phase Composition of Their Patina

I.F. Myronyuk; I.M. Koval; V.I. Mandzyuk; I.P. Yaremiy

doi:10.15330/pcss.17.3.430-434

Authors

I.F. Myronyuk Vasyl Stefanyk Precarpathian National University
I.M. Koval Vasyl Stefanyk Prekarpathian University
V.I. Mandzyuk Vasyl Stefanyk Prekarpathian University
I.P. Yaremiy Vasyl Stefanyk Prekarpathian University

DOI:

https://doi.org/10.15330/pcss.17.3.430-434

Keywords:

lead seals and stamps, patina coating, electrochemical corrosion

Abstract

The paper studied the elemental composition of lead alloys of appendage stamps and seals of Middle Ages, and the influence of impurity elements in the alloy and conditions for long-term storage of monuments on the course of corrosion processes and the formation of patina phase composition. Due to the influence of salts of orthophosphoric, hydrochloric and carbonate acids dissolved in the water environment on the artifacts surface patina coating is produced formed mainly of pyromorphite or pyromorphite and lead carbonate mixture. It was found that the corrosion rate of monuments depends essentially on the total content of Zn, Cd, Sn and Fe in lead alloy, which provide the protect for the main metal due to the electrochemical oxidation. Pink and brown colour of patina of certain attractions is associated with the pink colour of pyromorphite, which it takes as a result of isomorphic substitution of a small number of Pb atoms on Fe (III) ones. A colour of patine coating also depends on the content FeO, FeOOH and PbCO₃∙Pb(OH)₂.

References

[1] V.L. Janin, Aktovye pechati Drevnej Rusi X – XV vv. Tom І (Nauka, Moskva, 1970).
[2] O. Alf'orov, Sfragіstichnij shhorіchnik 2, 5 (2012).
[3] V.A. Anohin, Svincovye plomby velikogo knjazhestva Kievskogo (X – XIII vv.) (ID “Stilos”, Kiev, 2012).
[4] V.V. Nechitajlo, Katalog drevnerusskih pechatej H – HІІІ vekov. Tom І. Drevnerusskie pechati Velikih knjazej Kievskih i Mitropolitov Rusi (Izd-vo “Ukrainskaja konfederacija zhurnalistov”, Kiev, 2012).
[5] Rutherford J. Gettens, Studies in Conservation 6(1), 89 (1961).
[6] O.V. Hrinchenko, M.V. Kurylo, V.A. Mykhailov ta in., Metalichni korysni kopalyny Ukrainy (VPTs “Kyivskyi universytet”, Kyiv, 2006).
[7] D. Dobosh, Jelektrohimicheskie konstanty. Spravochnik dlja jelektrohimikov (Mir, Moskva, 1980).
[8] I.F. Myroniuk, I.M. Mykytyn, Elektrokhimiia ta yii praktychni aspekty (NAIR, Ivano-Frankivsk, 2016).
[9] O.O. Mysliuk, Osnovy khimichnoi ekolohii (Kondor, Kyiv, 2012).
[10] R.A. Lidin, L.L. Andreeva, V.A. Molochko, Spravochnik po neorganicheskoj himii. Konstanty neorganicheskih veshhestv (Himija, Moskva, 1987).