The Destructive/Non-Destructive Identification of Enameled Pottery, Glass Artifacts and Associated Pigments—A Brief Overview

Abstract

The birth of Chemistry can be found in two main practices: (i) the Arts du feu (ceramic and glass, metallurgy, i.e., inorganic and solid state chemistry) and (ii) the preparation of remedies, alcohols and perfumes, dyes, i.e., organic and liquid state chemistry). After a brief survey of the history of (glazed) pottery and (enameled) glass artifacts, the development of destructive and non-destructive analytical techniques during the last few centuries is reviewed. Emphasis is put on mobile non-destructive Raman microspectroscopy of pigments and their glass/glaze host matrices for chronological/technological expertise. The techniques of white opacification, blue, yellow, green, red, and black coloring, are used as examples to point out the interest of pigments as chronological/technological markers

Unravelling the glass trade bead sequence from Magoro Hill, South Africa: separating pre-seventeenth-century Asian imports from later European counterparts

“…Although the beads classified as K2-IP (Fig. 5) fit the morphological requirements, only one of the beads (Mag-k2-lb1) gave a Raman spectrum that places it in Group B. XRF measurements (Table 2) confirm that this bead is made of soda glass and its uranium (10.1 ppm) and aluminium (Al 7.63%) content also complies with that of K2-IP beads (U: 68 ± 68 ppm, mean Al 2 O 3 : 11.8%) [24]. The Raman spectra of the other beads place them in the soda-lime group, confirmed by XRF measurements (Al too low, Ca too high, absence of uranium and the presence of small amounts of antimony (Sb) and arsenic (As) probably added as opacifiers) and therefore they can be assigned to the European period.…”

“…antimony, arsenates, lazurite, etc. ), which are useful indicators of provenance and production period for beads arriving in Africa during the last 400 years [21,22,24]. Raman spectra recorded of pigments and opacifiers in this study are presented in Fig.…”

“…Cobalt, associated with silver (Ag), was detected as colourant in these beads. The source of cobalt is most probably from the Erzgebirge in Saxony [24,38,39]. Based on trace elements, four different sources of cobalt can be assumed for blue beads.…”

In situ study of stones adorning a silver Torah shield using portable Raman spectrometers

“…Raman spectroscopy is starting to be routinely used as a primary method for studying gemstones mounted in many historical objects in situ (Heinrich's cross dating from the late Middle Ages, [2] scepter of Faculty of Science of Charles University [3] ) or in the laboratory (golden chalices from the Einsiedeln Abbey crafted in the 17th century, [4] the Reliquary cross and Dorothy monstrance of the late Gothic period, [5] the cover of an elaborately decorated leather-bound manuscript, the Tours Gospel, 'Evangelia Quatuor' [6] ), analyses of pigments, [7][8][9][10] glass and glass products [11][12][13][14][15][16] and ceramics. [17,18] We present here the rapid and accurate in situ identification of stones using portable instruments equipped with 785-nm and 532-nm lasers, the second of them used for the identification of the red coral's pigments in resonance conditions.…”

Raman spectroscopy in art and archaeology

“…Both studies were directed at the identification of the pigments used by ancient artists and in both cases the complete destruction of the specimens was undertaken; Sir Humphry Davy especially commented on this undesirable although necessary aspect of his work. A classic review of Reaumur's work and other early investigators has appeared in Colomban [6]. Even in 1922, the situation had remained unchanged and Eccles & Rackham [7] in their classic publication on the wet chemical analyses of English, Welsh, Chinese and Continental porcelains in the Victoria & Albert Museum's collection had to destroy valuable and documentary pieces to achieve their objectives in the determination of the chemical composition of the selected specimens.…”