Characterisation of the white marble of two unpublished ancient ...

Per. Mineral. (2000), 69, 1, 49-62" PERIODICO di MINERALOGIAestablished in 1930An International Journal ofMINERALOGY, CRYSTALLOGRAPHY, GEOCHEMISTRY,ORE DEPOSITS, PETROLOGY, VOLCANOLOGYand applied topics on Environment, Archaeometry and Cultural HeritageCharacterisation of the white marble of two unpublished ancient Romanquarries on the Islands ofFourni and Skyros (Greece)LORENZO LAZZARINI* and STEFANO CANCELLIEREL.A.M.A., Dipartimento di Storia dell'Architettura, I.U.A.V., S. Polo 2468/B, I-30125 Venezia, ItalySubmitted, Janumy 2000- Accepted, March 2000A B STRACT. -Most outcrops of good qualitycrystalline marble of the Mediterranean countrieswere exploited in Roman times for the production ofblocks to be used for statuary and architecturalelements. Hence, a wide variety of marble wasemployed and is now found in archaeologicalexcavations. The precise determination of theprovenance of a marble object is of greatarchaeological importance, and is obtained in mostcases by the petrographic study of a thin section withanalysis of the C and 0 stable isotopes. Despite ofthe fact that it is highly developed, the alreadyexisting petrographic and isotopic data base of themost important marbles used in antiquity is stillinsufficient because of the incomplete knowledgeand study of all ancient quarries. The contribution ofthis research is to add new data on two unpublishedsmall Roman quarries discovered on the Greekislands of Fourni and Skyros. The marbles quarriedthere are very pure and characterised by a low-grademetamorphism which produced a limitedrecrystallization on the marine limestone protoliths.The fabrics are quite distinctive; the marble fromFourni shows a strong lineation and traces ofmetamorphic stress while that of Skyros ischaracterised by a polygonal mosaic equilibriumfabric.The isotopic data for the Fourni marbles varyfrom o13CPDB = 3.8 to 4.9, and o180PDB = -2.7 to*Corresponding author, E-mail: lorenzo@inav.unive.it-3.9. The Skyros marble vary from o13CPDB = 0.6 to1.9, and o180PDB= -4.2 to -7.1. These data havebeen compared with those of similar marbles used inantiquity.RIASSUNTO. -La maggior parte degli affioramentimediterranei di marmi cristallini di buona qualitavennero sfruttati in eta romana come siti estrattivi diblocchi da utilizzare per statuaria ed elementiarchitettonici. Da questo fatto deriva la grandevarieta di marmi che verigono trovati in scaviarcheolo gici. La precis a determinazione dell aprovenienza del marmo di un manufatto riveste unagrande importanza archeologica, ed e attualmenteottenuta nella maggior parte dei casi mediante1' accoppiamento dello studio petrografico di sezionisottili con l'analisi degli isotopi stabili del C e dell'O.Nonostante la banca dati petrografica e isotopicadei piu importanti marmi usati in antico sia moltosviluppata, essa e da considerare ancora insufficientea causa della non completa conoscenza e studio ditutte le cave mediterranee antiche.Il presente contributo consiste nell'incremento ditale banca con nuovi dati relativi a due piccole caveromane inedite scoperte nelle isole greche di Fournie Skyros.I marmi ivi estratti sono bianchi, molto puri ecaratterizzati da un metamorfismo di basso gradoche produsse una limitata ricristallizzazione dei dueprotoliti costituiti da calcari marini.Le loro strutture sono risultate piuttosto

50 L. LAZZARINI and S. CANCELLIEREcaratteristiche: quello di Fourni mostra una fortelineazione e tracce di stress metamorfico, mentre ilmarmo di Skyros evidenzia una struttura poligonaledi equilibrio con numerosi punti tripli. I datiisotopici del marmo di Fourni variano da 3,8 a 4,9 di813CPDB e da -2,7 a -3 ,9 di 8180PDB·Quelli del marmo di Skyros da 0,6 a 1 , 9 dib 13 CPDB e da -4,2 a -7,1 di 8180PDB·Questi dati sono stati confrontati con quelli dimarmi simili usati in antico.KEY WORDS: Marble, ancient quarries, Fourni,Skyros, petrography, isotopes.INTRODUCTIONIn recent years there has been considerableinterest on the part of specialists working inseveral archaeometric laboratories around theworld in the characterisation of the crystallinemarbles used in ancient monuments and worksof art. The main goal has been to create areference data base which could enable theprovenance of a marble artefact of historic andartistic value to be identified through simpleand affordable scientific analyses. Theimportance of such an identification forarchaeologists, architects and art historians, isbased on the possibility of attributing an objectto its producing atelier; on the indirectreconstruction of commercial connections andthe paths of maritime or terrestrial routes; onthe collection of data useful for theauthentication of the artefact and, finally, onthe finding of sources of the same marble forsubstitutions, restorations and copies. Manymuseums such as the Metropolitan Museum ofArt (New York), the British Museum(London), the Louvre (Paris), the MuseiCapitolini (Rome), the Ny Karlsberg Glyptotek(Copenhagen), and the AntikenMuseum Easel,have therefore started extensive campaigns oflaboratory analyses for the identification of themarble forming the most importantmasterpieces in their collections.At present there exists no single scientificmethodology that guarantees the positiveprovenancing of a marble sample of unknownorigin, and there has been very little research inthe field of non-destructive methods (Careri etal., 1992), which ideally should be preferred tothose needing the removal of a sample. Instead,the combination of two (e.g. ESR and C and 0-isotopes-analysis) or multiple, (e.g. traceelements, isotopic and petrographic analysis)destructive methods is currently used. Of all theabove-mentioned combinations, the one whichis most used, and most advanced in terms ofdeveloped data base is the petrographic study ofthin sections and C and 0 isotopic analysis(Gorgoni et al., in press). As regards these twodatabases, and in general those existing for allthe other methods, it should be specified thatthey are all limited to the most importantmarbles exploited in antiquity, such as the Greek(Pentelic, Parian, Naxian, Thasian, Lesbian) theMicroasiatic (Proconnesian, Dokymaean,Aphrodisian), and the Lunense (Carrara)marbles. Some data also exist on secondaryqualities such as those from ancient Iberia andGallia, etc., but they are not sufficient to coverall the possible sources of an ancient marbleartefact. In classical times in fact, most outcropsof crystalline marbles, especially the goodquality ones (compact, with homogeneous fabricand white colour, and possibly a fine grain-size),were exploited all around the Mediterranean,and travelled especially as blocks or half-workedpieces. Marbles with such good properties arequite common in the places cited above, and inmany other localities of Asia Minor, Greece andNorth-Africa. Many of these have never beenstudied archaeometrically, thus making thesource identification of a marble object oftenvery difficult.The lack of a complete scientific data baseof reference for all the ancient Mediterraneanmarble quarries undoubtedly underlies thisdifficulty.It is with the intention of expanding thepetrographic and isotopic data base of the whitemarbles used in antiquity that the results of ouranalyses of the marbles of two smallunpublished Roman quarries recentlydiscovered on the Greek islands of Fourni andSkyros (fig. 1) are here presented, together withother information of archaeological andhistorical interest.

Characterisation of the white marble of two unpublished ancient Roman quarries on the Islands... 51SKYROS ISLANDFOURNI ISLAND' 0SKYROS=60kmFig. 1 - Map with the locations of the ancient Roman quarries on the Island of Fourni and Skyros.

52 L. LAZZARINI and S. CANCELLIERETHE MARBLE OF FOURNI:RESULTS AND DISCUSSIONFourni is a very small Island (30 km2) in theEastern Aegean Sea between the larger islandsof Samos and Ikaria (fig. 1). Given itsfavourable position it has been frequented andinhabited since very ancient times. It is quitecertain that in classical times it was under thedominion of the Samians, and then of theRomans, but nothing is left that dates from theseperiods. Very little is also known of its geology,and it still has no detailed geological map.Geologically the island of Fourni belongsto the Pelagonian zone and is formed byterrains dating to the Trias (limestonesepimetamorphites)(Gem·galas, 1924; Koehne,1937). The main formations are mostly made ofmetamorphic rocks such as marbles, calcschists,chlorito-and-micaschists, and phyllites. Themarbles are present in the NE and SW areas ofthe island (Jacobshagen, 1986), and are mostprobably related to the larger marble-outcropsof the islands· of Ikaria and Samos, and ofMount Mykale in Turkey. The latter two wereexploited by the Greeks since archaic times, asdemonstrated for example by the kouroi (statuesof naked youths) in the Archaeological Museumof Pitagorio (Samos) and by all the architecturalelements of the temple of Athena Polias stillvisible at the ancient town of Priene. Themarble of Samos has never been studiedarchaeometrically; that of Priene wasinvestigated petrographycally and for its Ca/Srratio (Lazzarini et al., 1980).Nothing is known about the marble ofFourni: there are no ancient sources or modernstudies on it, its use and characteristics. Anancient quarry was worked into the outcroparound the bay of Petrokopio in the SW of theisland, very close to the sea. The quarry ispartly filled by collapsed material. Thepreserved part is small, being some 25 m long,with a front of 10 m maximum height withnumerous and nicely preserved cutting marks(fig. 2) of the types left by a «heavy pick»(Waelkens, 1992). These, the presence of manyunfinished and half-finished squared blocks,column-shafts, sarcophagi, with dimensionsrelated to the Roman foot (29.6 cm), togetherwith Roman potsherds scattered on the surfaceof the quarry area, are evidence of a Romanexploitation of this quarry. Most of theunfinished artefacts are gathered near the sea(fig. 3) where they were transported to be readyfor a shipment that never took place.Measurements of some of the pieces (in cm)are as follows:- 3 fragments of column shafts and drums(fig. 3): 1) length= 90, diameter= 105; 2) 90 x185; 3) 187 x 85. The second, and largest ofthese drums, may have been prepared for thecutting of «rotae» (disks) for flooring.- squared blocks (fig. 3): 102 x 332 x 71; 98x 127 x 75; 120 x 120 x 120; L-shaped block:thickness = 62 x 150 (long side) x 210 (shortside) x 90 (two ends of the L)-sarcophagus (fig. 4): length= 336, height=100, width = 130.Considering their half-finished state, theseare more or less multiples of 30 cm.Point chisels and quarry picks were used tosquare the pieces on site in order to avoid anyexcess load. This is also demonstrated by thepresence of several deposits of debris stillcontaining small blocks and column shafts (fig.5) at various stages of shaping. Quiteremarkable is the presence of an unfinishedsarcophagus which features an area in relief atthe centre of the coffin prepared for an eventualinscription. Also to be noted is the presence onthe site of a «gournia», a sort of small carvedbox made of marble which was filled withwater and used for tempering the iron tools.Buried in the water in front of the quany thereare also several squared blocks and other halffinishedpieces testifying to the lower sea levelin ancient times.The marble quarried at Petrokopio is of goodquality, showing a white colour mass (MunsellNeutral Scale = 9) (Munsell, 1967) withfrequent stripes of a milky-white (M. N. S. =9.5), or yellowish colour, and rarer gray spots(M.N.S. = 8.5). Its compactness and very finegrain-size must have made it easy to work,sculpt and polish.

Characterisation of the white marble of two unpublished ancient Roman quarries on the Islands... 53Fig. 2 -The ancient front of the quarry at Fourni withmarks of the heavy pick to the right.Fig. 3 -The quarry yard by the sea with accumulatedancient shaped marble blocks.Fig. 4- Fourni: the unfinished Roman sarcophagus.Fig. 5 - Foruni: detail of quarry-debris including smallsquared blocks and shaped columns.This marble has never been studiedscientifically and is not included among theCycladic and other Greek marbles so farstudied archaeometrically (Herz, 1992,Gorgoni et al., in press).Considering the quite limited size of thequarry and the homogeneity of the marble, 6small samples were taken from different areas,and 1 (sample F7) from an ancient block. Thesesamples were then subjected to petrographic

V1+:>.abr'l'>N>:;o"";:l0..n>znti1rm:;oti1cFig. 6 - Photomicrographs (N +, 40 x) of thin sections of the marble of Fourni showing: a) the fabric parallel to the E-W lineation; b) the fabric perpendicularly to thelineation; c) a weak deformation in the polysynthetic twinning and a quartz crystal; d) a zone with fine grain size and a N-S oriented fabric.d

Characterisation of the white marble of two unpublished ancient Roman quarries on the Islands... 55analysis in thin section, X-Ray diffraction and5 of them to isotopic analysis (McCrea, 1950).The results obtained are summarized in table 1.Under the microscope the marble shows aheteroblastic, sometimes homeoblastic lineatedfabric (Table 1) formed by frequently isoorientedcalcite crystals (fig. 6a) accompaniedby small trains of K-mica (sericite) andconcentrated veins formed by black particles ofcarbonaceous matter. The calcite crystalsfeature mainly curved boundaries, with rarerstraight ones (fig. 6b) sometimes forming triplepoints. The frequent deformation on the tracesof polysynthetic twining are indicative of somemetamorphic stress (fig. 6c). The average grainsize (determined by measuring a large numberof crystal' diameters) is around 0.6 mm, alsobecause of the frequent presence of zones withvery fine grain (fig. 6d); the MGS (MaximumGrain Size), an important fingerprintingparameter (Moens et al., 1988) varies from0.75 to 2.10 mm. The relative (internal) amount,-----, 6FOUR NIr-----,-----,-----,-----,-----+3-5 -4 -3 -2 -1 0Fig. 7The isotopic signature of the marble of Fourni.of accessory minerals is also reported in Table1. They comprise quartz (sometimeshydioblastic and including small needles ofrutile), K-mica in tiny needles, pyrite andfrequently associated small limonitic masses.Three samples (nos. 2, 5 and 7) gave traces ofdolomite by X-Ray diffraction. The isotopic54- 10 -9 -8 -7 -6-5 -4 -3 -2 -1 0Fig. 8 - Fourni (F) and Skyros (S) 013C vs 0180 variation ranges. Fields of the most important marbles used in antiquity areplotted for complarison. N = Naxos; PE= Mount Penteli; S = Skyros; D = Dokymeion; A= Aphrodisias; U = Usak; PA-l=Paros Stephani; PA-2 = Paros Lakkoi; C = Can·ara; T- 1/3 = Thasos; F = Fourni; PR= Marmara.

TABLE 1Petrographic and isotopic data of the white marblesjr01n Fourni and Skyros (Greece).IQUARRY Sample C.I. Qz M C O.M. D A.g.s. M.g.s. C.c.b. F 813C 8180FOURNI Fl 9 ± + ++ ± 0.68 2. 10 CURVED HE STRONGLY LINEATED 4.3 -3. 1WITH DEF.TWINSF2 9 ± ++ ± ± 0.66 1.3 1"HEF3 9 + ++ ± 0.60 0.75 CURVED- HE/HO STRONGLY LINEATED 4.4 -3,5STRAIGHTWITH LEVEL FINE GR.F4 9"± ± + ± I 1.22 CURVED- HE/HO4.3 -2.7STRAIGHTF5 9 ± ± +++ ± 0.6 1 1. 14 CURVED HE/HOF6 8.5 ± ± +++ 0.44 0.82"HE WEAKLY LINEATED 4.9 -2.9WITH DEF. TWINSr'F7 9""r-

Characterisation of the white marble of two unpublished ancient Roman quarries on the Islands... 57results expressed in the PDB standard (Table 1)show a variation of ()13C from 3.8 to 4.9, and of()ISQ from -2.7 to -3.9 (fig. 7).This marble should be considered as aproduct of localized low-grade (low-T, high-P)regional metamorphic processes which tookplace on pure marine limestones in the «greenschist»facies. Comparing the petrographic andisotopic data of the Fourni marble with similarfine-grained marbles used in antiquity (fig. 8),namely those from the ancient town ofDocimium (Iscehisar, province of Afyon,Turkey), from the island of Paros (CentralAegean Sea, Greece), Mount Penteli (Athens,Greece), and from Luni (Carrara, Italy), onemay remark that:- petrographically the marble of Fourni isquite distinct from all the other cited ones: itslineated fabric makes it distinguishable fromthose of Docimium, Paros and Luni. Pentelicmarble is quite similar to ours, but it has alarger average grain size (around 0.9 mm) anda much higher amount of accessory minerals,namely k-mica and chlorite. The marble ofPriene is always of grey colour, with a coarsergrain size and a larger M.G.S.- isotopically it may be confused only withthe marbles from Thasos (Thasos-3) and Paros­Stefani (Paros-1).In conclusion, combining the petrographicand isotopic data, the marble of Fourni is wellseparated from all the similar importantmarbles of antiquity considered above.THE MARBLE OF SKYROS:RESULTS AND DISCUSSIONSkyros is one of the several Islandsbelonging to the Sporades archipelago situatedin the North-Western Aegean Sea (fig. 1). It isquite small (21 0 km2), and hilly, but wellsituated geographically on the route from theEastern and Northern Aegean to the Island ofEuboea and Attica. It was inhabited fromproto-historic times (Sapouna-Sakellaraki,1998) and became a flourishing place in Greektimes. The Roman consul Sulla conquered it in86 B.C., and not long after the island becamevery productive for Rome. The Augustanperiod marked the start of the exploitation of abeautiful polychrome carbonate breccia whichis commonly called Marmor Scyrium or«Scyreticum», and «Breccia di Settebasi»(Lazzarini, 1999). The former name appears ona fragment of the famous edict on the price ofvarious goods issued by the emperor Diocletianin 301 (Gnoli, 1988), where the marble is listedat the rather cheap cost of 40 denarii (silvercoins) per cubic foot. The low price may beexplained by the fall in the cost of marble thatoccurred in Rome in the IV c. following theconsiderable stockpiling of marbles at the«statio marmorum» (marble-yard) of Ostia andthe beginning of the decadence of the capital.Another possible explanation is that this pricedid not relate to the breccia (which in theoryshould have been more expensive, at least 150«denarii», like other decorative stones such asthe very similar «Marmor Lucullaeum», whichanyway was no longer available at the time ofthe edict), but to the white marble that will bedescribed here. White and gray marbles, likethe Proconnesian and the Lesbian are in factlisted at 40 and 50 «denarii» respectively. Theirlow price, like that of the Skyros marble wasjustified by the availability of large quantitiesand by the location of their quarries close to thesea, which made transportation and shipment toall Mediterranean destinations very easy.Strabo (IX, 5, 16) also offers evidence of thedifferent costs of white and coloured marblesby indirectly stressing the importance of thelatter. Finally, we may consider the whiteSkyrian marble as a cheap substitute for moreprestigious white, similarly fine-grained Greekmarbles like the Parian and Pentelic.As in the case of the Fourni marble, we knownothing about the history of the use, diffusion,etc., of the marble from Skyros, except that itwas used locally from archaic -times. forstatuary (examples are in the archaeologicalmuseum of Skyros), and in the classical periodfor architectural elements as in the templededicated to Apollo at Chora (Defner, 1923).Judging by the size of existing ancient quarries,

58 L. LAZZARINI and S. CANCELLIEREand by the artefacts left on the island, the use inRoman times increased considerably, probablyleading to exportation.The geology of the island of Skyros is quitecomplex, as is immediately evident from thestudy of the geological map published byIGME, the Hellenic Geological andMetallogenic Institute, (Jacobshagen andMatarangas, 1972). The outcroppingformations range from igneous rocks(peridotites, dunites, andesites, dacites, spilitesand tuffs) of the Lower Tertiary, tosedimentary rocks (limestones, marls,sandstones, flysch, etc.) dating from thePermian-Carboniferous to the Neogene, to thevolumetrically dominant metamorphic rocks(gneiss, phyllites, schists of various types,calcite-dolomite-marbles, serpentinites,ophicalcites) dating from the Middle Triassic tothe Upper Cretaceous. According to Melentis(1973), the island belongs to the Pelagonianzone of the Hellenides, more precisely to theEohellenic Tectonic N appe, and roughlyconsists of a basement formed by gneiss andmica-schists, overlain by a phyllite series. Themarbles lie in structural conformity above thephyllites. The Upper Cretaceous limestonesgenerally overlie the basement and the marblestransgressively, both locally penetrated byultrabasic intrusions and serpentinites, whilesmall bodies of andesite intruded into thelimestones in few places.The calcite-dolomite marble occupies a verylarge part of the island and has an estimatedthickness of 1000 m. It dates to the MiddleTriassic-Jurassic (?) and includes fine-grainedto coarse marbles, mostly thick bedded, withcolours varying from pure white to dark gray,and polychrome meta-breccias. The latter wereextensively quarried in Roman times in variousparts of the island (Aghios Panteleimon, TreisBoukes, Kourisies: Lazzarini, 1999) and onsmall islets like Balaxa, Rinia and Skiropoula(Defner, 1923; Dworakowska, 1972), and havealready been the subject of an archaeometricstudy (Lazzarini and Turi, 1999).Of the limestones, only a small portion hasbeen transformed into a marble and/or has thenecessary characteristics to be used asdimension material, namely the marbleoutcropping in the area to the North of the Bayof Pefkos (fig. 1). In this area numerousquarries were open in Roman times, mostly forthe exploitation of the breccia, but also for theproduction of a beautiful white, fine-grainedmarble used locally for columns and otherarchitectural elements, table pedestals, tubs,some of which, as mentioned above, were verylikely exported: this should be proved byarchaeometric analysis. Unfortunately theancient quarries have been ex ten si velydestroyed in recent years by the intensivemodern extractive activity carried out since theearly 1900s. There exist several small ancientquarries from which a nice pure-white, finegrainedmarble was extracted in Roman times inthe area called Bouno (= mount) and on the isletof Kolouri, both to the NW of Agh.Panteleimon. The main extractive area was thatstill called Kolones from the Roman columnsfound there, where Defner visited severalancient quarries in 1923, some of whichcontained cisterns and traces of aqueducts andsettlements. The largest of these quarries is in aplace called Lakous. It is unfortunately stillproductive and is therefore undergoing thecomplete destruction of the ancient traces ofexploitation. The quarry is situated on MountDekatria, at about 260 m above sea level andforms a sort of amphitheatre open to the E-NE.It is quite large, being some· 150 m long with afront of 20-30 m high (fig. 9). It yields abeautiful white marble in the lower levels, withoccasional thin yellow veins and grey spots, anda more homogeneous white-greyish marble inthe upper ones. These colours are connected toconcentrated fine particles of limonite andcarbonaceous matter respectively. By 1997 onlysome parts of the quarry (to the extreme lowerleft, fig. 10) still retained the typical chevronlikequarry marks of ancient exploitation left bythe use of a Roman heavy pick, the rest beingmuch modified by modern cutting of the marblewith diamond wire and explosives. Duringrecent operations to clear the quarry area of theancient debris, a large number of Roman

Fig. 9 -The ancient quarry of Lakous at Skyros with evidence, in theforeground, of modern exploitation.Fig. 10- The left part of the quarry with the best preserved traces of Romanexploitation.\):::s-2s::i"c:;·-

0\0abr'l'>-N>-! CS :::0::l0..n>-znrnrm::VrncFig. 13- Photomicrographs (N +, 80 x) of thin sections of the marble of Skyros showing: a) a perfect homeoblastic polygonal fabric with abundant triple points; b) azone with very fine grain size; c) a porphyroblast of calcite; d) a weakly recrystallised zone with relics of the protolith still showing a stylolith with stylo-cumulatedcarbonaceous particles.d

Characterisation of the white marble of two unpublished ancient Roman quarries on the Islands... 61squared blocks were found: a few of them (twosmall columns and some squared blocks) werestill lying on the site (fig. 11 ), others had beencut into slabs in past years, and some hadaccumulated in the yards of the marbleworkshop of the quarry owner (fig. 12),together with a few blocks of breccia. Someblocks show the typical stepped shape of blocksprepared for the cutting ofslabs. Thedimensions of some of these blocks (consideredas whole pieces), of other rectangular ones, andof a fragmentary column, are:78 X 104 X 255; 80 X 95 X 220; 80 X 90 X 220;80 X 90 X 280; 89 X 96 X 251; 64 X 69 X 170;62 X 74 X 155; 71 X 80 X 182; 90 X 111 X 211;92 x 109 x 208; column: 128 x 52 (d.).A lot of breccia and marble was quarriedafter the First World War by the Britishcompany Marmor Limited, and intenseexploitation continued for several decades:since the island had specialised stonecutters italso served as a worksite and deposit for blocksof other stones (like the ophicalcite of Tin os) tobe shipped for the Greek and internationalmarket. The port of Pefkos, very close to thequarrying area of Agh. Panteleimon, was wherethe marble was shipped from in Roman andrecent times; many squared blocks are stillaccumulated there: their dimensions areindicative of the period of extraction.A total of 10 samples were taken fromdifferent parts of the quarry of Lakous andfrom the ancient debris and blocks: they weresubjected to the same analyses as above.The results of the petrographic and isotopicanalyses are collected in Table 1. In general themarble of Skyros is very compact andhomogeneously pure-white (M.N.S. = 9.5), butsometimes it shows thin yellow or pinkishveins, and grey spots (M.N.S. = 8/8.5). Theaverage grain size is very small (around 0.15mm); the M.G.S. varies from 0.26 to 3.20 mm.The fabric ismostly homeoblastic, ofpolygonal type with abundant triple pointsformed by calcite crystals with straightboundaries (fig. 13a). Sometimes present areSKYROS0-8 -7 -6 -5 -4 -332-1813cFig. 14 - The isotopic signature of the marble of Skyros(*from literature, Lazzarini and Turi, 1999).zones with very fine grain size (fig. 13b ), andrare, isolated porphyroblasts of calcite (fig.13c) often showing slightly bent polysynthetictwins. Apart from traces of K-mica, iron oreminerals (mostly limonite and hematite) andcarbonaceous particles (fig. 13d), this marble isremarkably pure calcite (only two samplesshowed the presence of dolomite). The isotopicanalysis of 5 samples gave 813C ranging from0.6 to 1.9, and ()180 from -4.2 and -7.1. Tothese isotopic data may be added two otherpublished analyses (Lazzarini and Turi, 1999)relating to a sample of white marble from aunknown modern quarry of Skyros (813C =0.50, ()180 = -5.75), and to a sample of greymarble taken from an outcrop close to the Bayof Achilles (813C = 1.0, ()180 = -11.8).Like that of Fourni, the Skyrian marbleshould be considered the product of a lowgrade metamorphism mainly producing a weakrecrystallisation of calcite.Comparing these results with the sameselection of similar marbles used in antiquityand cited above for Fourni, (Table 1, fig. 8) it isnoticeable that:- petrographically, the white marble fromSkyros is unique for its very regularequilibrium- polygonal fabric and very finegrain size. This fabric makes it easilydistinguishable from the marbles of Docimium,Paras, Mount Penteli and that of Fourni, whileit may sometimes be confused with that ofLuni, but its finer grain size and larger M.G.S.

62 L. LAZZARINI and S. CANCELLIEREare quite distinctive also with respect to thislast material- isotopically, the field of Skyrian marblepartly overlaps those of the marbles fromDocimium, Aphrodisias, Naxos and Usak(fig. 8).Again, as for the marble of Fourni, bycombining the petrographic and isotopic dataone can easily distinguish the white marble ofSkyros from all the marbles mentioned above.In conclusion, we are confident that thecharacterisation of the marble of the twoquarries of Petrokopio (Fourni) and Lakous(Skyros) will make it possible not only toidentify these marbles among the white onesused in the Eastern Aegean area, but also todetermine whether marble was exported fromthese two islands.ACKNOWLEDGMENTSThe authors are indebted to Dr. Paolo Mel, Venicefor his precious information about the island ofFourni. This research was financed by CNR (theItalian National Research Council) through the«Progetto Strategico Beni Culturali».REFERENCESCARERI G., LAZZARINI L. and MAZZACURATI V.(1992) -Angular distribution of light diffusedfrom laser-irradiated crystalline marbles.Potential use for identification purposes. InAncient Stones: quarry, trade and provenance»M. Waelkens, N. Herz, L. Moens (Eds.), ActaArchaeologica Lovaniensia, Monographia, 4,Leuven, 237-242.DEFNER M. (1923)- Ta apKaw A-aropew rnaLKVpov. ApKatoAOytlCT\ El!l£PlO", 102-116.DWORAKOWSKA A. (1972) Starozytnekamieniolomy Skyros i wysp karyjskich. Materialydo inwentaryzacji. Archeologia, XXIII, 7-21.GEORGALAS G. (1924) - Sur la constitutiongeologique des iles Phourni (entre Nikaria etSamos). C.R. Acad. Sci., Paris, 179, 601-604.GNOLI R. (1988)- Marmora Romana, 2nd ed.,Roma.GORGONI C., LAZZARINI L., PALLANTE P., TURI B.,(1998) -An updated and detailed referencedatabase for the main Mediterranean marblesused in antiquity, transactions of Asmosia, FifthInt. Conference, Boston June 11-15, (in press).HERZ N. (1992) - Provenance determination ofNeolithic to classical Mediterranean marbles bystable isotopes. Archaeometry, 34, 2, 185-194.KoEHNE F. (1937)- Petrographie und Geologie derFourni-Insel bei Samos. N. Jb. Miner., 73, 1-78.JACO B SHAGEN F. (1986) - Geologie vonGriechenland. Berlin-Stuttgart, 176-177.JACO B SHAGEN V. and MATARANGAS D. (1972) -Skyros Island, Geological Map of Greece1:50.000, IGME, Athens.LAZZARINI L., MOSCHINI G. and STIEVANO A.M.(1980) -A contribution to the identification ofItalian, Greek and Anatolian marbles through apetrological study and the evaluation of the Ca/Srratio. Quaderni della Soprintendenza ai BeniArtistici e Storici di Venezia, 9, 9-33.LAZZARINI L. ( 1999) -Manna Sciro e Semesanto,nuove cave antiche. Recupero e Conservazione,27,64-69.LAZZARINI L. and TURI B. (1999)Characterisation and differentiation of the Skyrosmarbles (Greece) and the Medici 's Breccias(Italy). In: «Archeomateriaux, marbres et autresroches» M. Schvoerer (Ed.), Actes de la IVe Conf.Int. ASMOSIA IV, Bordeaux 9-13.X.95, 117-123.McCREA J.M. (1950) - On the isotopic chemistryof carbonates and a paleotemperature scale. J.Chem. Phys., 18, 849-857.MELENTIS J. (1973)- The geology of Skyros. Bull.Geol. Soc. of Greece, 10, 298-322.MOENS L., Roos P., DE RUDDER J., DE PAE P E P.,VAN HENDE J. and WAELKENS M. (1988)- Amulti-method approach to the identification ofwhite marbles used in antique artifacts. In:«Classical marble: geochentistry, technology,trade» N. Herz, M. Waelkens (Eds.), Nato ASIseries E, 153, Dordrecht, 243-250.MuNSELL COLOR COMPANY ( 1967) - MunsellNeutral Value Scale.SA P OUNA-SAKELLARAKI E. (1998)- Skyros. Athens,62 pp.W AELKENS M. ( 1990) - Technique de carriere,prefar,;onnage et ateliers dans les civilisations(monde grec et romain). In: «Pierre Eternelle, duNil au Rhin, carrieres et prefabrication»,Bruxelles, 53-72.