TY - JOUR
T1 - English delftware (c. 1770) from Bristol, Lancaster and Liverpool
T2 - A composition study using Raman spectroscopy and electron microscopy
AU - Edwards, Howell G.M.
AU - Jay, William H.
N1 - Funding Information:
The authors acknowledge the use of the Raman spectroscopy facilities within the Department of Chemistry, Monash University and the FIB and NanoSEM 450 microscopes within the Monash Centre for Electron Microscopy (MCEM), a node of Microscopy Australia. Felicity Marno, Stockspring Antiques, is thanked for sourcing the Liverpool and Bristol tiles The anonymous lender of the tiles is thanked for allowing the tile fragments to travel to Australia to enable the research to be conducted. Mrs Barbara Blenkinship is thanked for making available sherds from the Lancaster excavations and also for the provision of several additional tiles. Mr. Ray Jones, Worcester, is also thanked for the loan of a Bristol sherd. Neither author received any external funding.
Publisher Copyright:
© 2022 Elsevier B.V.
PY - 2022/10/15
Y1 - 2022/10/15
N2 - Nine decorated lead–tin glazed earthenwares, colloquially termed ‘delftware’, produced in c. 1770 in Bristol, Lancaster and Liverpool, England, have been analysed non-invasively by Raman spectroscopy and electron microscopy. The body paste used to manufacture these west coast wares was attained by the blending of highly dolomitic [CaMg(CO3)2] “blue” clay sourced from Carrickfergus, County Antrim, Ireland, with locally sourced clays. Thus, the resulting body fabric of these wares contains significant MgO enabling them to be differentiated from MgO-free London manufactured delftware. The glazes employed all contain arsenic, obtained as a cobalt impurity or by deliberate addition. The presence of this unvolatilised arsenic in the glaze has then reacted with the lead during firing at temperatures approaching 1000 °C and then further reacted with calcium and magnesium to form needle-like crystals of lead arsenates in the form of mimetite [Pb5(AsO4)(Cl,OH)], schulténite [Pb(AsO3OH)], β-roselite [Ca2Co(AsO4)2·2H2O], hedyphane [Ca2Pb3(AsO4)3Cl], wendwilsonite [Ca2Mg(AsO4)2·2H2O] and/or adelite [CaMgAsO4(OH)] during high temperature firing.
AB - Nine decorated lead–tin glazed earthenwares, colloquially termed ‘delftware’, produced in c. 1770 in Bristol, Lancaster and Liverpool, England, have been analysed non-invasively by Raman spectroscopy and electron microscopy. The body paste used to manufacture these west coast wares was attained by the blending of highly dolomitic [CaMg(CO3)2] “blue” clay sourced from Carrickfergus, County Antrim, Ireland, with locally sourced clays. Thus, the resulting body fabric of these wares contains significant MgO enabling them to be differentiated from MgO-free London manufactured delftware. The glazes employed all contain arsenic, obtained as a cobalt impurity or by deliberate addition. The presence of this unvolatilised arsenic in the glaze has then reacted with the lead during firing at temperatures approaching 1000 °C and then further reacted with calcium and magnesium to form needle-like crystals of lead arsenates in the form of mimetite [Pb5(AsO4)(Cl,OH)], schulténite [Pb(AsO3OH)], β-roselite [Ca2Co(AsO4)2·2H2O], hedyphane [Ca2Pb3(AsO4)3Cl], wendwilsonite [Ca2Mg(AsO4)2·2H2O] and/or adelite [CaMgAsO4(OH)] during high temperature firing.
KW - Cobalt blue pigmentation
KW - Delftware
KW - Electron microscopy
KW - Lead arsenate
KW - Lead–tin glaze
KW - Raman spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=85132578990&partnerID=8YFLogxK
U2 - 10.1016/j.saa.2022.121458
DO - 10.1016/j.saa.2022.121458
M3 - Article
C2 - 35687989
AN - SCOPUS:85132578990
SN - 1386-1425
VL - 279
JO - Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
JF - Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
M1 - 121458
ER -