Raman and FTIR spectroscopy applied to the conservation report of paleontological collections: identification of Raman and FTIR signatures of several iron sulfate species such as ferrinatrite and sideronatrite

摘要: Fossil materials that contain iron sulfide are well known for their instability when exposed to oxygen and humidity. This term however combines a great variety of showing different types damages. Most them consist crystal efflorescence appearing on the surface inside matrix. In this work, methodology was determined analysis these damages by use Raman infrared spectroscopy. The signatures large set sulfates were characterized. Specific attention paid sideronatrite ferrinatrite, which two associated sodium/iron(III) sulfates, bands partially assigned. Analysis performed selection 11 damaged fossils showed degradation products: besides one case appeared be synthetic resin close polyvinylchloride acetate, applied with brush fossil surface, all products belong sulfate group. However, many iron-free such as gypsum, halotrichite, epsomite, or pentahydrite found, often in association sulfates. case, despite presence matrix, no could detected. shows ‘pyritic fossil’, commonly used collection managers, is not appropriate it oversimplifies reality. A name ‘sulfide-containing fossil’ would more suitable. Copyright © 2012 John Wiley & Sons, Ltd.