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Naturally irradiated fluorite as a historic violet pigment: Raman spectroscopic and X-ray diffraction study

SYSNO ASEP	0441814
Document Type	J - Journal Article
R&D Document Type	Journal Article
Subsidiary J	Článek ve WOS
Title	Naturally irradiated fluorite as a historic violet pigment: Raman spectroscopic and X-ray diffraction study
Author(s)	Čermáková, Zdeňka (UACH-T)_SAI Bezdička, Petr (UACH-T)_{SAI, RID, ORCID} Němec, I. (CZ) Hradilová, J. (CZ) Šrein, V. (CZ) Blažek, Jan (UTIA-B)_{RID, ORCID} Hradil, David (UACH-T)_{RID, SAI}
Source Title	Journal of Raman Spectroscopy. - : Wiley - ISSN 0377-0486 Roč. 46, č. 2 (2015), s. 236-243
Number of pages	8 s.
Language	eng - English
Country	GB - United Kingdom
Keywords	fluorite ; pigment ; fluorescence bands ; diffraction lines broadening ; irradiation
Subject RIV	CA - Inorganic Chemistry
R&D Projects	GAP103/12/2211 GA ČR - Czech Science Foundation (CSF)
Institutional support	UACH-T - RVO:61388980 ; UTIA-B - RVO:67985556
UT WOS	000349891900006
EID SCOPUS	84923016334
DOI	10.1002/jrs.4627
Annotation	Naturally irradiated violet fluorite, a cubic CaF2mineral, is a rare historic pigment. Its documented usage in Europe stretches from ca. 1450 to ca. 1550. The intensely coloured violetish black naturally irradiated fluorite is commonly called antozonite, which is only vaguely defined based on its dark colour and specific odour emanated during grinding. In the published literature, there have been some discrepancies about its Raman spectrum. Therefore, sixteen samples of antozonite were analysed by Raman (micro-)spectroscopy using five different excitation laser wavelengths (445, 532, 633, 780 and 1064 nm), which revealed specific bands located below500 cm 1 probably related to radiation-caused defects. Their intensity increasedwith increasing violet colour saturation, thus providing a specification for antozonite’s definition. Spectra excited at 445 and 780nmcontained also numerous broad bands above 500 cm 1, which seem to be caused by the presence of rare earth elements. The structural damage of antozonite samples has been assessed by X-ray diffraction and related to their lightness using analysis of image histograms. The obtained results have been applied in the analysis of micro-samples of a Late Gothic altarpiece located in an Italian Court in UNESCO city Kutná Hora, Czech Republic, which contained exceptionally large grains of deep violet fluorite identified as antozonite.
Workplace	Institute of Inorganic Chemistry
Contact	Jana Kroneislová, krone@iic.cas.cz, Tel.: 311 236 931
Year of Publishing	2016

Number of the records: 1