Jones, R.E.

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S PARTA: M E N E LAIO N ICD-124Seven examples of Group 1 and three of Group 2 were analysed chemically by optical emissionspectroscopy for the determination of some of the major elements apart from silica. The methodologywas the same as that adopted in the Fitch Laboratory in the corresponding study of paintedwall plasters from Knossos by Cameron et al. (1977). From the calcium oxide determination theequivalent lime (calcium carbonate) concentration was calculated. From the results shown in TABLE D.1below, it is readily apparent that most of the Group 1 examples are high quality lime plasters;their compositions are similar to those obtained from painted plaster at Mycenae, Tiryns and elsewhereon the Mycenaean Mainland ( Jones in press). 3 and 4 are less pure lime plasters. As expected, themud plasters are of variable composition: 8 can be regarded as a calcareous earth, while 9 and 10 arenon calcareous earths.TABLE D.1: Partial chemical compositions of some plasters. 1–7 lime plasters, and 8–10 mud plasters.Calcium expressed as (equivalent) percentage calcium carbonate, aluminium, magnesium and iron expressed as percentageelement oxides.CD-124Appendix DSome technical observations on the painted plasterfrom the Menelaionby R. E. JonesFollowing the macroscopic examination of the (large) majority of the plaster, it proved possible toidentify two broad groups:Rather hard white plaster, some grit (occasional pebbles), someimpressions of thin ?reeds. Generally uniform calcined lime butoccasional large chunks of partially or totally untreated limestone.Majority of Group I plasters show signs of burning. Smooth outersurface but not obviously polished. Rough backing of lime plasterwhere it bound to mud substrate. Plaster thickness average 2.5cm, varying from 1.5 to 3.5 cm. Some variants:(a) a white, crumbly plaster of variable quality and thickness. In 8examples the layer is less than 1 cm, the surface smooth andpolished.(b) Coarser, thicker version, with rough, poorly finished surface.Mud plaster: red in colour but usually burnt to dark-grey. Variablequality.50–75% of assemblage?25%Group Frequency Characteristics1: white lime plasters2: mud plastersSample Ca Al Mg Fe1 >95 <0.5 <0.1 <0.12 >95 <0.5 0.5 <0.13 60 <0.5 0.4 <0.14 53 <0.5 <0.1 0.25 >95 <0.5 0.2 16 >95 <0.5 <0.1 <0.17 >95 <0.5 <0.1 <0.18 60 5.3 1.5 29 5 10.7 0.5 510 3 7.3 0.2 4AP P E N DIX D CD-125The painted plaster was first examined under the stereomagnifier, and then, following the experiencerecently gained with the study of fresco material at Knossos (Cameron et al.) 1977, a qualitativeassessment of the nature of the different pigments, particularly the blues, was made on a number ofspecimens by non-destructive X-ray fluorescence (XF); the painted surface and in many cases theplaster were analysed. Like the work on the bronzes from the Menelaion, whose results are reportedelsewhere in this volume, the analyses were carried out in the apothiki at Aphyssou. This proved aquick and most effective means of identifying unusual or problematic pigments, some of which in theevent were subsequently investigated by X-ray diffraction (XRD) by Dr S. E. Philippakis (at NSCRDemokritos) and, for two samples, by Dr V. Perdikatsis (at IGME). The limitations of XRF, however,should be made clear: the analysis would only indicate the principal elements present in the pigment,and care had to be taken with specimens that had multiple paint layers and/or had remnants of soilconcretion on the surface. The reason for the emphasis on the blue pigments at the Menelaion is theirrelative frequency and diversity on Aegean LBA wall paintings ( Jones 2005).SF Colour XRF XRD CommentSM 74 J24/25 11 Red H, C, Q (plaster C, Q)SM74 DV 2 502 Red Fe rich Red painted onto mud plasterSM74 K25L25 8 217 Orange Fe richSM 74 DV 2 510 Orange Fe richSM 73 P 3 804 OrangeBlue Fe richCu andFe richSM 74 K25 3 123 Greenbrown Fe richSM 74 J24/25 19 Blue I, C, Q (plaster C, Q)SM 76 N-P3 4 36 Blue Cu richSM75 DVII N 4 210 Blue Cu richSM73 P 11 828 Blue Cu richSM 74 H24 20 73 Blue No CuSM74 J25 9 18 Blue ?CuSM75 DVII N 4 212 Blue Fe rich Blue and red applied first,followed by whiteSM74 B J24/25 4 30 Blue-grey Fe richSM73 R 1402 Blue-grey Fe richSM75 D 1 2 253 Blue Fe and Mn rich C, Q, I Amorphous pigmentSM73 S 3 1020 Blue Fe rich C, Q, I Amorphous pigmentSM73 S 1000 Blue over red Fe richoffering tableSM74 H25 4 81 Blue Cu richSM74 J24/25 19 45 Blue Cu and Fe rich EB; Q, I, ?muscovite Larger dark blue crystalsmica (VP) underlie the smallerE. Blue crystalsSM75 DVII 2 224 Blue Cu and Fe rich EB; Q, I, ?muscovitemica (VP)SM73 R 1 1444 Blue Fe richSM73 R 3 1430 Blue Fe richSM73 R 1 1413 Blue Fe richSM73 X 4 Blue Fe rich Blue underlying red underlyingblueSM74 J24 17 25 Blue Cu richSM73 S 3 1004 Blue grey Fe and Mn richSM ? N 4 211 Blue Fe richSM73 R 2 1403 Blue Fe richSM73 R 1 1405 Blue Fe and Mn richSM74 N23 DD Plaster H, Q, CconcretionVP = Dr V Perdikatsis; EB = Egyptian Blue; Q = quartz; C = calcite; I = illite; H = haematiteS PARTA: M E N E LAIO N ICD-126The principal result of interest is the occurrence of at least two types of blue: first the synthetic copper-rich Egyptian Blue, second the presumably naturally occurring iron-rich mineral, and third their mixture.There is no surprise in finding the first of these pigments in a LBA Aegean context for it was widelyemployed in the Minoan and Mycenaean worlds ( Jones 2005, table 2). The only detail that may beadded is that the colour is attributable to copper and not apparently to bronze, as has been noted, forinstance, at Mycenae. But the nature of the other type of blue is more elusive: it is neither riebeckitenor glaucophane which were minerals commonly used in central Crete and Akrotiri on Thera. Atpresent, there seem to be two possibilities: either the material is amorphous but contains iron, or thecolour is attributable to clay minerals such as mica, contaminated with an iron-bearing compound.Such findings have been closely paralleled at Chania where a programme of examination and analysishas recently been completed (Photos-Jones, et al., forthcoming). The presence of three examples ofblue containing both iron and manganese is puzzling and needs to be further investigated.The presence of an iron-rich green is also of interest but regrettably it was not characterisedmineralogically. The reds and oranges are surely iron oxides.B I B LI OG RAP HYCameron, M. A. S., R. E. Jones and S. E. Philippakis, 1977. ‘Scientific analysis of frescoes from Knossos’, BSA 72,121–84.Jones, R. E., 2005. ‘Technical studies of Aegean Bronze Age wall painting: methods, results and future prospects’,in L. Morgan (ed.), Aegean Wall Painting: A Tribute to Mark Cameron. BSA Studies 13. London: 199–228.Photos-Jones, E., R. E. Jones and A. J. Hall, forthcoming. ‘A technical of fresco fragments from excavations atKhania’, Swedish Institute Khania Excavation volume.AC K NOWLE D G E M E NTSR. E. J. thanks Dr V. Perdikatsis and S. E. Philippakis for kindly carrying out XRD analyses.

Some technical observations on the painted plaster from the Menelaion

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Some technical observations on the painted plaster from the Menelaion

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