Pigments—Iron-based red, yellow, and brown ochres

Mastrotheodoros, Georgios P.; Beltsios, K.

doi:10.1007/s12520-021-01482-2

Cited by 40 publications

(32 citation statements)

References 173 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, iron fades and gradually “disappears” in the areas of high lead content simply because the iron-rich primary layers lay below numerous layers of lead-rich paints (lighter tones and highlights—layers 3 and 4 in Figure 2 a–c). However, in the areas of maximum iron intensities, there is also a strong presence of manganese (Mn) ( Figure 3 d), and this hints towards the employment of umber (i.e., a Mn-rich iron ochre) [ 28 , 39 ]. Moreover, these areas coincide with dark contours and shadows, where an umber pigment was presumably used.…”

Section: Resultsmentioning

confidence: 99%

Scanning X-ray Fluorescence Data Analysis for the Identification of Byzantine Icons’ Materials, Techniques, and State of Preservation: A Case Study

et al. 2022

Self Cite

View full text Add to dashboard Cite

X-ray fluorescence (XRF) spectrometry has proven to be a core, non-destructive, analytical technique in cultural heritage studies mainly because of its non-invasive character and ability to rapidly reveal the elemental composition of the analyzed artifacts. Being able to penetrate deeper into matter than the visible light, X-rays allow further analysis that may eventually lead to the extraction of information that pertains to the substrate(s) of an artifact. The recently developed scanning macroscopic X-ray fluorescence method (MA-XRF) allows for the extraction of elemental distribution images. The present work aimed at comparing two different analysis methods for interpreting the large number of XRF spectra collected in the framework of MA-XRF analysis. The measured spectra were analyzed in two ways: a merely spectroscopic approach and an exploratory data analysis approach. The potentialities of the applied methods are showcased on a notable 18th-century Greek religious panel painting. The spectroscopic approach separately analyses each one of the measured spectra and leads to the construction of single-element spatial distribution images (element maps). The statistical data analysis approach leads to the grouping of all spectra into distinct clusters with common features, while afterward dimensionality reduction algorithms help reduce thousands of channels of XRF spectra in an easily perceived dataset of two-dimensional images. The two analytical approaches allow extracting detailed information about the pigments used and paint layer stratigraphy (i.e., painting technique) as well as restoration interventions/state of preservation.

show abstract

Section: Resultsmentioning

confidence: 99%

Scanning X-ray Fluorescence Data Analysis for the Identification of Byzantine Icons’ Materials, Techniques, and State of Preservation: A Case Study

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…High iron and manganese contents may also explain the greenish, brown, and black hues of the henna powders and samples HT-11, HT-16, and JT-4. In fact, natural earth pigments containing iron oxides and/or hydroxides or iron-rich clays can have a wide range of shades from deep purple and brown to red, yellow, and olive green [ 21 ], while manganese oxides are generally linked to brown colors [ 22 ].…”

Section: Resultsmentioning

confidence: 99%

Understanding the chemical and mineralogical composition of commercial henna and jagua tattoos and dyes—a multi-analytical approach

et al. 2022

View full text Add to dashboard Cite

Temporary tattoos and dyes constitute a great analytical challenge in relation to the regulatory control of their ingredients. Most of these commercial products are not labeled according to their content and their chemical nature is highly diverse. Therefore, it is necessary to analyze these complex samples to evaluate the potential presence of metallic impurities, to ensure the safety of cosmetic products contributing to health protection. This study proposes a multi-analytical methodology, which includes handheld X-ray fluorescence (h-XRF) and X‐ray diffraction (XRD), complemented by variable pressure scanning electron microscopy coupled with energy-dispersive X‐ray spectrometry (VP-SEM–EDS) to fully characterize 34 commercial samples of jagua and henna tattoos and dyes. The approach allowed the identification of the main constituents providing complementary compositional data and differences between sample types were established. In addition, information on the degree of natural pigments homogeneity was also obtained. The results’ discussion considering the current European cosmetics regulation may be useful to support the drafting of safety requirements and specific regulation.

show abstract

“…The significant amount of lead and iron is observed in the yellow, and the brown of the most superficial layer is visible in the altar of Apollo and the two torsos. The association of these two elements suggests the use of lead mixed with ochres, or the use of sandyx (Pliny, Naturalis Historia, 35, 30, 40) [27,29]. The colocalization of iron and lead is observed by mapping: the distribution of these elements corresponds to the areas where colour was applied (Figure 19b).…”

Section: Identification Of the Pigments In The Superficial Layermentioning

confidence: 99%

Ancient Restoration in Roman Polychromy: Detecting Aesthetic Changes?

2022

View full text Add to dashboard Cite

Few instances of material evidence for ancient colour restorations have been documented over the last 20 years, during which time the scientific approach to the study of polychromy has been defined. This article presents eight new cases of ancient restoration of colour from the Roman Imperial Age. By combining observations in visible and UV light and video microscopy with a micro-stratigraphic approach, MA-X-ray fluorescence spectroscopy, and contextual archaeological data, we have observed evidence which could suggest an aesthetic change in the use of colour between the 2nd and 4th centuries CE: from polychrome and multitone effects to the use of monochromatic, flat, and uniform colour finishes.

show abstract

Pigments—Iron-based red, yellow, and brown ochres

Cited by 40 publications

References 173 publications

Scanning X-ray Fluorescence Data Analysis for the Identification of Byzantine Icons’ Materials, Techniques, and State of Preservation: A Case Study

Scanning X-ray Fluorescence Data Analysis for the Identification of Byzantine Icons’ Materials, Techniques, and State of Preservation: A Case Study

Understanding the chemical and mineralogical composition of commercial henna and jagua tattoos and dyes—a multi-analytical approach

Ancient Restoration in Roman Polychromy: Detecting Aesthetic Changes?

Contact Info

Product

Resources

About