5 Natural Sili ate Glasses
Conferen e
Book of Abstra ts
August 22 24, 2013
Museo di Storia Naturale
Aula Strozzi
5 Natural Sili ate Glasses Conferen e Book of Abstra ts International Advising Committee: B. Weeks (Nashville) K. Heide (Jena) B. Champagnon (Lyon) D.B. Dingwell (Muni h) E. Paris (Camerino) S. Jahn (Potsdam) G.S. Henderson (Toronto) J.W. Zwanziger (Halifax)
E.D. Zanotto (Sao Carlos)
A. Suzuki (Sendai) S.K. Lee (Seoul) L. Galoisy (Paris) S. Manoli (Venezia) Organization Committee: R. Moretti (Napoli) G. Giuli (Camerino) G. Pratesi (Firenze) D.R. Neuville (Paris)
This workshop is supported by the Commission on Physi s of Minerals of the
International Mineralogi al Asso iation
The 5 th
Natural Sili ate Glasses meeting is a satellite workshop of the Golds hmidt
Conferen e 2013. The previousfour onferen es have taken pla ein Alfred(1983),Prague
(1987),Jena (1996)and Lyon (2002).
The onferen e is organized around four main topi s: Natural Glasses, Sili ate Melts
and Glasses, Glasses inAr haeology, and Glasses forIndustrial Appli ations.
The NaturalSili ate Glassesmeetingwillprovide aforumfordis ussion ofboth
exper-imentaland omputationalresultsrelatedtoglass stru ture andphysi al- hemi al
Program i
Organization ii
Foreword iii
Sili ate Melts Session
Keynote talk - Russell JK - Modelling natural sili ate melt vis osity 1
Neuville DR - Alspe iationin sili ate glasses andmelts: new idea and oldstory? 2
Ci oni MR - The ee t of alkali [Na/(Na+K)℄ ratio on Fe spe iation in phonoliti glasses 3
Moretti R - The redox state of sili ate melts and glasses: why should we pursue withempiri al
approa hes? 4
Natural Glasses Session
Keynote talk - Koeberl C - Natural glasses formed by meteorite impa t 5
Gimeno D - Basanite-alkalirhyolite mingled glass bombsof the initial y le(O tober 2010)
sub-marine eruption atLa Restinga, El Hierro island, CanaryIslands (Spain) 7
Amalberti J - He and Ardiusivity in basalti glasses and melts 8
Giuli G - Fe oxidation state andwater ontentof moldavite tektites 9
Takada A - Stru tural simulation on sili a glasses and rystals 10
Industrial Glasses Session
Keynote talk - Fal one R - Produ tion and opti al properties of soda-lime-sili a glasses 11
Milke R - Evolution of irides ent glass weathering layers and some onsequen es 12
Jahn S - Stru ture and transport properties of al ium and magnesium aluminate melts and
glasses: A mole ular dynami s study 13
Conte S - Ar haeometri al analyses of late andpost Roman glass fromButrint (Albania) 14
Forna elli C - New developments in early industrial stained glasses 15
Pier e EM - Glass orrosion: integration of experimentation and modeling to develop a
me ha-nisti understanding of glass-water interfa ial rea tions 16
Stabile P - Kineti sof iron redu tion in anhydrouspantelleriti glasses 18
Tannou I - Properties and stru tural role of iron in sili ate meltsand glasses 19
Ia ovino K - Sulfur in alkaline melts: An experimental study 20
Floury P - Implementation of the Panum Crater dome (California). Rheologi al study and
dif-fusion of waterin the pumi e and obsidian 21
Ferra uti P - Determining the provenan e of Mediterranean obsidian artifa ts 22
Moretti R - The amphoteri behavior of water in sili ate melts from the point of view of their
ioni -polymeri onstitution 23
Tarrago M - Rheologi al onstraints in welded pyro lasti alkaline rhyolites: a ase study from
NuraxiFormation,SW Sardinia,Italy 24
Arzilli F - Spherulites in tra hyti melts 25
Benzi F - V lo al environmentin phosphate glasses 26
Bartoli O - Natural sili ate glasses from the deep rust 27
Gimeno D - Ar haeometri study of samples glass from the Ciutadella de Roses site (Empordà,
Girona), NE Spain 28
Mugoni C- Glasses ontaining opper slag for erami glazes 29
Siligardi C - Alumina/aluminaLa-glass omposites fordental prostheti appli ations 30
Modelling natural sili ate melt vis osity Russell JK 1 ,GiordanoD 2 , HessKU 3 , DingwellDB 3
1Earth,O ean & Atmospheri S ien es, Universityof British Columbia,Canada; 2Earth
S ien es, Universityof Torino,Italy;
3Earth & Environmental S ien es, Ludwig-Maximilians-Universität, Germany;
krusselleos.ub . a
Abstra t
The vis osity of sili ate melts ontrols magma transport dynami s, eruption style and
rates of physi o hemi alpro esses in natural magmas. A predi tive modelfor vis osity of
natural sili ate melts at geologi al onditions has been a long-term goal in earth s ien e
for over half a entury. During that time, the number of vis osity models has in reased
and the rate of in rease is a elerating. This growth in the vis osity modelling industry
is driven by innovations in the experimentallaboratory over the last 30years allowingfor
vis ositymeasurementsoverlargerrangesoftemperatureand omposition. Herewereview
the models and modelling strategies for melt vis osity from the original work of Shaw [1℄
and Bottinga and Weill [2℄ to now [3-7℄. We suggest that the best models are those that
onform to the operational de nition of a model [8℄; in addition to a strong predi tive
apability, models must omprise: well- onstrained logi al propositions (i.e. onstru t)
with ne essary, testable onsequen es. Forexample, the GRD [7℄modelpredi ts the
non-Arrhenianvis osity of naturalsili ate meltsas afun tion of Tand melt omposition,but,
analsopredi tandbetestedagainstothertransportpropertiesin ludingT
g
,meltfragility,
anda tivationenergy. Su htesting,byhundreds ofusers,has delineatedthe strengthsand
weaknesses of the GRD model. As we begin to develop the next-generationmodel, we are
urrentlyassessingwhetherthekeyis: i)moredata,ii)betterdata,oriii)abetterphysi al
hemi al guidingmodel?
Referen es
[1℄ Shaw H.R.(1972),Am. Jour. S i. 272,870-893.
[2℄ BottingaY.and Weill, D.(1972), Am. Jour. S i. 272, 438-475.
[3℄ BakerD.R. (1996),Am. Mineral. 81, 126-134.
[4℄ HessK.U. andDingwell D.B. (1996), Am. Mineral. 81,1297-1300.
[5℄ AvramovI. (2007),J. Vol . Geoth. Res. 160,165-174.
[6℄ HuiH.and ZhangY.(2007), Geo h. Cosmo h. A ta 71,403-416.
[7℄ GiordanoD.et al. (2008),Earth&Planet S iLets,271, 123-134.
Al spe iation in sili ate glasses and melts: new idea and
old story?
NeuvilleDR 1
1Géo himie & Cosmo himie, CNRS-IPGP, Sorbonne ParisCité, 1 rueJussieu, 75005 Paris;
neuvilleipgp.fr
Abstra t
The rsthumanglassesweremade3500BC.Itwasessentiallysoda-limesili ateglass. Toimprove
the hemi al resistan e, the thermal properties and in rease thevis osityit is interesting to add
aluminum in these sili ates. And now aluminosili ate melts and glasses are materials widely
usedinseveralindustrialappli ations(glass,glass- erami and erami materials),andimpli ated
in large-s ale geologi al pro esses. Their properties and stru ture, imposed by their hemi al
omposition, drivefor instan e the eruptive dynami s of vol anoes aswell asindustrialpro esses
of theglass-makingindustry.
Butwhatisthespe iationofthealuminumandhowitvariesa ordingtothe hemi al
ompo-sitionandto thetemperature? Thealuminumappearsessentiallyinfour or ve fold oordination
in glasses and melts. In alkali aluminosili ate ompositions, Alis essentially in four fold
oordi-nation whereastheproportion of [5℄
Alin reases withearth-alkaline substitution, or withalumina
ontentandwithtemperature. Inthe aseofalkali aluminosili ateglassandmelts, Alis
ompen-sated byalkali element and asa fun tion of alkali element (Li, Na, K) a new glass order an be
observed. In a se ond part, we an observe thepresen eof [5℄
Alinearth-alkaline aluminosili ate
ompositions. And itsproportion variesasa fun tionof Aland T. Inparti ular, asafun tion of
temperature, [5℄
Alplaydierent roles, lose than glasstransition temperature [5℄
Al an bea new
network former and atmore hightemperature [5℄
Al an beinsure thenetwork dynami s.
Inall ase, [4℄
Aland [5℄
Alplayimportantroleonthestru tureandpropertiesofsili ateglasses
The ee t of alkali [Na/(Na+K)℄ ratio on Fe spe iation in phonoliti glasses Ci oni MR 1 ,Giuli G 1 ,Paris E 1 ,Ertel-Ingris h W 2 ,Dingwell DB 2
1S hool of S ien e and Te hnology - Geology Division,University of Camerino (I);2Dept.
Earth andEnvironmentS ien es - LMUMün hen (D)mariarita. i oniuni am.it
Abstra t
Sili ateglassesofphonoliti ompositionshavebeensynthetisedtoinfertheee tofthe[Na/(Na+K)℄
ratio on theFestru tural roleand,as nal goal,on thephysi al properties.
Fe an existinsili atemelts ina varietyof oxidation statesand oordinationgeometries[1-2℄
and variation of the relative proportions of these spe ies imply variations in <FeO> distan es
andbondstrenghts,thusae tingglass/melt polymerisation,Fe molarvolumes, meltdensityand
vis osity[3℄. The phonoliti ompositions have been hosen to ll la k in literature dataand to
explorethebulk ompositionsforwhi htheoreti almodelsforFeoxidationstateandmeltvis osity
give lessa urate results. Thisstudy will possibly ontributeto improve theempiri al equations
andthetheoreti almodels developed until now[4-5℄. ThePhonoliti Glassessynthetisedat room
pressureandinarangeofoxygenfuga ity(log(fO
2
)from-0.68to-11)will beusefultoinferifthe
alkali ratio in these onditions will in uen e the lo alenvironment around divalent andtrivalent
Fe.
Inthisstudy,byusingFeK-edgeXAS spe tra(bothXANESandEXAFS),we an determine
theFestru tural role(oxidationstate, oordinationnumber, bond distan es)ofphonoliti glasses
to infer the in uen e of Temperature, [Na/(Na+K)℄ ratio (0.0, 0.25, 0.5, 0.75, 1.0, respe tively)
andredoxenvironment. Furtherstudiesareinprogressinordertoassessifthe[Na/(Na+K)℄ratio
alsoin uen esthe physi al propertiesofthemelts (i.e. vis osityand alorimetri measurements).
Referen es
[1℄ WilkeM. etal. (2001), Ameri anMineralogist 86,714-730.
[2℄ GiuliG. etal. (2011), Ameri anMineralogist 96,631-636.
[3℄ MysenB.O.,Ri hetP.(2005), Sili ateglasses and melts. ElsevierS ien e.
[4℄ KressV.C., Carmi haelI.S.E. (1991), Contributions to Mineralogy and Petrology 108, 82-92.
The redox state of sili ate melts and glasses: why should
we pursue with empiri al approa hes?
MorettiR 1;2;3
1Dipartimento di Ingegneria Civile,Design. Edilizia e Ambiente, Se onda Università degli
Studidi Napoli,Aversa(CE), Italy; 2IstitutoNazionale di Geo si a e Vul anologia sezione
Osservatorio Vesuviano, Napoli,Italy; 3Department of Geology, St. Mary's University,
Halifax, Nova S otia, Canada; roberto.morettiunina2.it
Abstra t
Melt evolutionand properties inEarth S ien es andglass-making industry is heavily ae tedby
redox equilibria, espe ially be ause of their impa t on the melt/glass stru ture. Redox
equilib-ria in melts are not only sensitive to hanges in intensive parameters, espe ially T and oxygen
fuga ity (fO
2
), be ause extensive parameters ( omposition) have major ee ts. This hemi al
ontrol,whi h in ludes amphoteri behaviourof some omponent, hinders a dire tappli ation of
experimentally alibratedredoxequilibria tomeltsystemsanddemandsunderstandingofthelink
between redox, a id-base properties and stru ture, whi h is very often overlooked, parti ularly
in Earth S ien es. The need of te hniques for determining the oxidation state of magmas from
iron and/or sulfur redox ratios has pushed s ientists to yield omposition-based semi-empiri al
equations,without mu hinterest forthe understandingof howele tron transfertakespla e, thus
disregardingtrue,oratleastmostplausible,redoxex hangeso urringinmelts. Notse ondary,it
hasgeneratednotations(i.e., hemi alequilibria)inwhi hstandardstates,spe iesand omponents
aremixed. Nowadays, thegreatadvan ement inthe performan es ofspe tros opi te hniques
al-lowsafull hara terizationofoxidation, oordinationandspe iationstateofheterovalentelements,
whereas, onthe theoreti alside,progressesinpolymeri modeling formelt mixing propertiesand
ab-initio simulations of mole ular sili ate and aluminate lusters provide a basi framework to
build more omprehensive modelsabout therea tivityof multiplevalen e state elementsin
mag-mas, aswell as inindustrial systems. It is theee tive three-way link between these approa hes
thatwillallowbringingtogetherstru tureandthermodynami sintoasingleinterpretative
frame-workableto exploittherelationshipbetween a id-baseandredoxproperties,thus ontributing to
ll our urrent gap ofknowledge onthe formal P-T-fO
2
Natural glasses formed by meteorite impa t
Koeberl C 1
1Department of Lithospheri Resear h, Universityof Vienna,Althanstrasse 14, A-1090
Vienna, Austria; hristian.koeberlunivie.a .at
Abstra t
Impa t rateringisanimportant geologi alpro essinthesolarsystemthatae tsallbodieswith
solid surfa es. The Earth has been subje ted to a large number of impa ts of large meteorites
(asteroids) and omets over its history; some impa t events have in uen ed the geologi al and
biologi alevolutionoftheplanet. Currently 184impa t ratershavebeenidenti edontheEarth's
surfa e. Identi ation of impa t raters requires on rmatory eviden e, su h as the presen e of
meteoritefragments(ortra esof meteoriti material), and/orthepresen eof sho kmetamorphi
ee ts inthe ae tedro ks. Sho ked mineralsand high pressure polymorphs are ommon sho k
metamorphi ee ts, but ro ks melted by the sho k pressure and/or hightemperatures involved
analsobepresent. Distin tivesho kee tsarenotlimitedtothedeformationor transformation
of target ro k minerals at pressures < 40 GPa. Higher sho k pressures, espe ially > 50 GPa,
produ e in reasingly high residual temperatures in the target ro ks through whi h they pass.
In any impa t, large or small, a signi ant volume of the target ro k lose to the impa t point
will be raised to post-sho ktemperatures > 1500 Æ
C, su ient to melt and de omposeminerals
that are unae ted by the lower temperatures produ ed innon-impa t geologi al environments.
Su hmeltingandde ompositionrea tions,observedinthero ksandglassesofimpa tstru tures,
an serve as independent eviden e of meteorite impa t events. The high temperatures involved
also serve to homogenize the hemi al omposition of the resulting melts and to reset isotopi
systems usedin radiometri age measurement, so thatsu himpa t melts areextremely valuable
indeterminingthe age of the impa tevent and theresulting rater.
The most ommon indi ator ofsu h impa t-produ ed high temperatures is theo urren eof
le hatelierite,orsili aglass,whi hindi atestemperatures1750 Æ
C,farabovetherangeofnormal
near-surfa e geologi al pro esses. The formation oflarge and smallbodiesof meltedtarget ro ks
(from mm-size to thousands of km 3
in volume) is a ommon hara teristi of meteorite impa t
events. During the initial stages of impa t, the more intense sho kwaves ( 40 GPa) generated
nearthe impa tpoint produ e near-instantaneous heating to extreme temperatures ( 2000 Æ
C)
throughout a large volume of the surrounding target ro k. Theresulting impa tmelts mayform
small glassy bodies that are eje ted from the developing rater or may produ e larger dike-like
and sill-like bodies ofigneous ro kthatremainwithin theresulting stru ture.
Smaller impa t melt bodies, mm to m in size and generally glassy, may be eje ted from
the impa t rater, oftento regional or global distan es, as individual splash-form obje ts, e.g.,
spherules and mi rospherules, dumbbells, droplets, and other aerodynami allyshaped forms. On
deposition, theseobje ts oftena umulate indistin t layersor aswidely-distributedstrewn elds.
Tektites and mi rotektites are the best-known and most-studied of these eje ta deposits, but a
variety of other glass-ri h eje ta deposits, of both Pre ambrian and Phanerozoi ages, have also
o ur as individual obje ts omposed either of dense glass or of s oria eous and vesi ular melt.
Many of these glassy bodies are learly asso iated with a de nite or possible impa t stru ture,
e.g., Meteor Crater (Arizona), Lonar (India), Aouelloul (Mauritania); Henbury (Australia); Rio
Cuarto (Argentina); Darwin (Australia), and various others. There are also some o urren es
of s attered glass fragments for whi h no impa t rater has yet been identi ed, su h as Libyan
DesertGlass. In some ases, itwasthedete tion ofan extraterrestrial omponent inglassesthat
allowed on rmationoftheimpa toriginofageologi alstru ture;su hidenti ationisdonewith
a variety of geo hemi al tools, espe ially tra e element ontents and the isotopi omposition of
Basanite-alkali rhyolite mingled glass bombs of the
initial y le (O tober 2010) submarine eruption at La
Restinga, El Hierro island, Canary Islands (Spain)
Gimeno D 1
1Dpt.Geoquimi a, Petrologia iProspe iò Geològi a, Fa . Geologia, Universitat deBar elona,
/Martì i Franquès, s/n, 08028 Bar elona (Spain); d.gimeno.torrentegmail. om
Abstra t
The A submarine eruption lose to the La Restinga village (south of El Hierro island, Canary
Ar hipelago,Spain)startedaroundO toberthe11 th
2011andwas onsidered on ludedatMar h
2012. During some weeksthe eruption wasmanifested byadis olored plume (green) of dissolved
gas (and probably suspended ne-sized parti les) marking the site of submarine vents on the
sea surfa e, and by the pun tual emission of a rare type of de imeter to meter-sized buoyant
pyro lasts, ovoid in shape, formed by two types of mingled magma (a bla k thin sideromelane
rust with a white pumiti ore). The rst unequivo al emission of this kind of pyro last was
at O tober the 13 th
2011, the last 22 O tober. Rhyolite-basanite omposite mingled pyro lasts
Restingolite pyro lasts are formed by two parts intimately mingled: a white mi rovesi ulated
pumi e, alkali rhyoliti in omposition and a deep green-bla k glassy basanite with porphyriti
(pheno rysts<3%)andlo allyma rovesi ulartextures. Thebasanite onstitutestheskinofthe
pyro lasts. whilethe inner partis formedbyplanarpumiti dis ontinuous plasti fragments
roll-wrappedwithbla kpartingsofbasanite. Lo ally,thebasanite learlylooksvitreouswith on oidal
fra ture (sideromelane). Taking into a ount geo hemi al data, isotopi data, termogravimetri
data, porosity, size and morphology of vesi les and bombs (among other data) this note will
illustrate the plausible eruptive me hanism, the at least balan ed parti ipation of basanita and
rhyolite volumes (till now explains 1:10ratio of rhyolite respe t basanite), involved inthe initial
weeksoftheeruption, inferreddepthofbasanite-rhyoliteintera tion andthesigni an e interms
He and Ar diusivity in basalti glasses and melts Amalberti J 1 ,Burnard P 1 ,Laporte D 2
1CRPG-CNRS,Vandoeuvre-lès-nan y, Fran e; 2LMV,Clermont Ferrand,Fran e;
amalbert rpg. nrs-nan y.fr
Abstra t
Thenoblegasesarewellknowntoolsfortra kingthedegassingofmagma,andpro essesimportant
for understanding vol ani eruptions. The diusion of noble gases an also be used as a probe
for understanding the behaviour of volatiles in sili ate liquids and glasses. Due to experimental
di ulties, He and Ar (and other noble gases) diusivities are poorly onstrained in natural
sili atesat magmati onditions [1-2℄. Inorderto addressthisla kofnoblegasdiusiondata, we
have measured He and Ar diusivitiesin sili ateglasses using lassi al inva uo stepped heating
approa hes [3℄.
Our results show that He and Ar diusivities onverge at high temperature, as do the
dif-fusivities of the individual Arisotopes ( 40;38;36
Ar), su h that their diusivities areequal at T>
750 Æ
C. Thisobservation is onsistent withthetheoryofdiusion ompensation whi h predi ts
an isokineti temperature dueto orrelated a tivationenergies (E
a
's)and pre-exponential fa tors
(D
o )[4℄.
The ompensationtemperatureplaysanimportantroleforunderstandingvolatilefra tionation
during magma degassing. Littleor no noblegas fra tionationshould o ur at temperatures lose
to or above the ompensation point; similarly, noble gas isotopi fra tionation an only o ur
duringlowtemperaturepro essesandnotduringthedegassingitself[5℄. Thisbehaviour anmost
probablybeextended toother volatile spe iesinthemagma.
Referen es
[1℄ LuxG.(1987), GCA.v51, p1549-1560.
[2℄ Nowaketal. (2004),GCA. v68, p5127-5138.
[3℄ M Dougalland Harrison(1988),Ox. Univ. Press.
[4℄ HartS.R.(1984), EarthPlanet. S i. Lett. v70 p297.
Fe oxidation state and water ontent of moldavite tektites Giuli G 1 ,Ci oni MR 1 ,Cestelli-GuidiM 2 ,Pratesi G 3 ,KvashninaK 4 ,GlatzelP 4 ,Paris E 1 , Koeberl C 5
1S hool of S ien e andTe hnology, University of Camerino (I);2INFN, Laboratori
Nazionalidi Fras ati (I);3Museo di StoriaNaturale, Universityof Floren e (I);4ESRF,
Grenoble (F);5Natural History Museum, Vienna (A); gabriele.giuliuni am.it
Abstra t
Moldavites aretektiteswhi h arethought toberelated totheimpa tevent that formedtheRies
rater inGermany. They aredistributed in a strewn eld a ross Che k Republi , Germany and
Austria at distan es ranging from 200 to 450 km fromthe sour e rater [1℄. A set of moldavites
fromtheBohemian, MoravianandChebsub-strewn eldshavebeenanalysedbyX-rayAbsorption
Spe tros opy (XAS) and FTIR spe tros opy in order to get quantitative information on the Fe
oxidation state and water ontent. Most moldavites show Fe 2+ /(Fe 2+ + Fe 3+ ) ratios 0.1
0.05, similar to tektites from the other strewn elds studied by XAS [2-4℄, Mössbauer [5-7℄ or
wet hemistry [8℄. Also the average Fe oordination number (whi h is intermediate between 4
and 5) is inagreement withprevious studies[2-4℄. However, few moldavites studied heredisplay
Fe 2+ /(Fe 2+ +Fe 3+ ) ratiosof 0.150.05 andup to 0.22.
Transmission FTIR data on the same samples allowed to determine water ontents ranging
from60to200ppm. No orrelationhasbeenfoundbetweenwater ontent andFeoxidationstate.
This means that thehigh temperature of theimpa t melt forming themoldavites annot be the
only responsible forboth thelowwater ontent andtherelatively low Fe oxidation state.
Preliminary data are also presented here on few samples of layered moldavites whose water
ontent displaya strongzonation mimi king thelayer orientation.
Referen es
[1℄ Trnka M. andStanislavH.(2002), Bulletinof the Cze hGeologi al Survey,77,283-302.
[2℄ GiuliG. etal. (2002), Geo him. Cosmo him. A ta,66, 4347-4353.
[3℄ GiuliG. etal. (2010a), Geol. So . Ameri amSpe ial Paper465,645-652.
[4℄ GiuliG. etal. (2010b), Geol. So . Ameri amSpe ialPaper465,653-660.
[5℄ RossanoS.etal. (1999),Physi s and Chemistryof Minerals26,530-538.
[6℄ DunlapR.A. etal. (1998),J. ofNon-Cryst. Solids223, 141-146.
[7℄ DunlapR.A. etal. (2004),J. ofNon-Cryst. Solids337, 36-41.
Stru tural simulation on sili a glasses and rystals
Takada A 1
, 2
1Resear h enter, Asahi Glass Co, 1150 Hazawa- ho, Yokohama 221-8755, Japan;
2Department of Earth S ien es, University College London W1E6BT,UK;
akira-takadaag . om
Abstra t
Mole ular dynami s simulation has been used to investigate the similarity and dissimilarity in
dynami al stru tural hanges between sili a rystals and glasses. Many simulation studies have
been performed for quartz, ristobalite and sili a glasses [1-3℄, however, there is s ar ely any
simulation studies on tridymite. The stru tural building blo k is thesame between in tridymite
and ristobalite, nevertheless, stru tural hanges due to the thermal ee ts is more omplex in
tridymitethanin ristobalite. Su h omplexityhindersthetheoreti alstudy. First,thestru tural
hanges of tridymite phase due to thermal ee ts are investigated by using mole ular dynami s
simulation. Next,the al ulated omplexstru tural hangesare omparedwiththoseoftheother
stru tures su h as ristobalite and glasses. Finally, we dis uss thesimilarities and dissimilarities
indynami alstru tural hanges interms ofmi ros opi stru ture.
Referen es
[1℄ Takada A.etal. (2004),J. Non-Cryst. Solids345&346,224.
[2℄ Takada A.etal. (2007),J. Eur. J.Glass S i. Te hnol. B48,182.
Produ tion and opti al properties of soda-lime-sili a
industrial glasses
Fal one R 1
1Stazione Sperimentale delVetro, Via Briati 10,Veni e-Murano, Italy; rfal onespevetro.it
Abstra t
Soda-lime-sili a (SLS) glass is the most widely used of all ommer ial types of glass. This type
of glass omposition is mainly used for manufa turing glass ontainers (e.g. bottles, jars) for
foodstusandbeverages,householdglasswareandwindowpanes. Theseprodu tsareprodu edby
meltingabat h ofappropriately weighedquantitiesofrawmaterials; themanufa turingpro ess
in ludes ve mainssteps: bat h preparation, melting, ning, forming, and post forming. Opti al
properties are one of the most important feature of SLS glass produ t. For glass ontainers the
hoi eofthe olormainlydependsontworequirements,foodpreservationandmarketing. Colorless
glass ontainers promote the visibility of the ontained produ t but provide poor prote tion to
photosensitive foodstu, whereas olored yellow-green and amber glass ontainers provide the
highest levelof prote tion to photosensitive foods and beverages. Flat glasses are also produ ed
with dierent opti al features basing on the requirements of the nal end produ t appli ation
(building, automotive, and furniture). In industrial glasses, olor is produ ed by the sele tive
absorptionof radiationinthe visiblerangebytransitionmetalions (e.g.,iron, hromium, obalt,
opper,manganese)added to thebat h asoxidesorother ompoundsinsmall quantitiesinorder
toprodu ethe desiredglass olor. Moreover,sin epolyvalent oloringionsprodu edierent glass
olorsat dierentoxidation states,themonitoring andthestabilityoftheredoxstate ofthemelt
Evolution of irides ent glass weathering layers and some
onsequen es
MilkeR 1
1Freie UniversitätBerlin, Institut fürGeologis he Wissens haften, Malteserstr. 74-100, 12249
Berlin, D; milkezedat.fu-berlin.de
Abstra t
Irides ent weathered glass is well known from ar haeologi al obje ts. The opti al ee t haslong
been explained by the evolution of laminated weathering layers. The me hanism responsible for
thislaminationseemstoremaininthedark,however, andmightbeofgeneralimportan eto glass
weathering resear h.
Together with several olleagues I have analysed the surfa es of beer bottles thrown away
on Australian Opal elds a few de ades ago, that all show irides en e. The multi-method
ap-proa h in ludes opti al mi ros opy, ele tron mi roprobe analysis, X-ray dira tometry, infrared
spe tros opy,Raman spe tros opy, fo ussed ionbeam extra tion, s anning transmissionele tron
mi ros opy, high-resolution TEM, ele tron energy loss spe tros opy, and thermal indu ed mass
spe trometry oftheRb-Srand Sm-Nd isotopesystems.
Thesurfa eweatheringlayers onsistofanamorphousopalinesubstan e. Itsuptakein
hemi- alelementsandisotopesindi atesthatthe surfa eweatheringlayershaveformedbyanex hange
pro ess between a salinar soil uid and the original bottle glass. There is an absolutely sharp
interfa e between theoriginalglassandtheweatheringlayers. Theopalweatheringlayer is
stru -tured into dense layers of onstant thi kness in the 150 nm range separated by porous layers.
This self-stru turing is explained by a dissolution-pre ipitation me hanism with subsequent loss
of waterfrom in reasinglypolymerising opal.
Glass surfa es provide linksbetween geosphereand biosphere. The weathering layers provide
substratesforsingle ell organisms,whiletheirides en eee tseemstointerferewiththemating
Stru ture and transport properties of al ium and
magnesium aluminate melts and glasses: A mole ular
dynami s study
Jahn S 1
1GFZ GermanResear h Centre forGeos ien es, Potsdam (D); jahngfz-potsdam.de
Abstra t
Cal iumandmagnesium aluminatesarerefra tory materialsofte hnologi al importan e. Froma
glassphysi s perspe tive, al ium aluminates areof spe ialinterest asthey arevery fragile glass
formers. Therapid hangeinphysi alproperties,forinstan eofthevis osity,ofsu hsystems lose
totheglasstransitionisthoughttoberelatedto hangesintheatomi stru turebetween themelt
and theglass. Re ently,x-rayand neutrondira tionexperimentsaswell asmole ular dynami s
simulations wereperformedto investigate thestru ture ofthesu hmelts andglasses [1-4℄. Here,
newresults from extensive mole ular dynami s simulations arepresentedthatlinkthe stru tural
evolutionof al iumandmagnesiumaluminate meltsduring oolingtotheirtransportproperties,
whi h in ludes theshear vis osity, self-diusion oe ients and the thermal ondu tivity. From
a stru tural point of view, we will espe ially dis uss the abundan e of stru tural motifs su h as
four- and ve-fold oordinated Al, OAl
3
tri lusters or the onne tivity of Ca- and Mg- entered
polyhedraasafun tion of temperature and quen hrate.
Referen es
[1℄ HennetL.etal. (2007),J.Phys.: Condens. Matter 19,455210.
[2℄ Jahn S.(2008), Am. Mineral. 93,1486-1492.
[3℄ DrewittJ.W.E.(2011),J. Phys.: Condens. Matter 23,155101.
Ar haeometri al analyses of late and post Roman glass
from Butrint (Albania)
ConteS 1 ,Arletti R 2 ,Vandini M 3 ,Chinni T 3
1Department of Chemistryand EarthS ien es, University of Modena andReggio Emilia(I);
2Department of Earth S ien es, Universityof Torino(I);
3Department of Cultural Heritage, University of Bologna(I); sonia. onteunimore.it
Abstra t
InLate Romanperiod,Butrint ity(SWAlbania), wasone of themost important seaportof the
eastern Mediterranean,due to its very favorable position and its long human presen e (from the
5 th
entury BC to the modern age). The ity seems to have parti ularly ourished after being
de laredaRoman olonyunderAugustusin31BC,butevenaftertheRomanperiod,Butrintwas
still at the enterof thetraderoutes to the Eastern regions. During thear haeologi al ampaign
of 2011 dire ted byDavid Hernandez (Universityof Notre Dame - US), aimed at identifying the
eastern border of the Butrint Roman Forum, several glass artifa ts, dated to the late Roman
period,werere overed. Inthisstudyweanalysed43fragmentsofglass(38transparent,5opaque)
ofdierent obje ts(drinking glass,bowls,mosai tesserae)datedfromthe4 th
tothe6 th
enturies
AD. The aims of this work are: i) understand the raw materials, the manufa turing te hniques
employed for glass produ tion and understand their evolution through the time; ii) produ e a
orre t lassi ation of pie esof un ertain date; iii) interpret thee onomi development and the
trademodelsofthisarea. The hemi al analyseswereperformedbyele tronmi roprobe (EMPA)
formajorandminorelementsandbyICPmassspe tros opy(LA-ICP-MS)fortra eelements. The
hemi al results indi ate that, after theex lusion of some outilers, the samples an be lassi ed
intotwogroups: i)produ edwithnatronas uxingagent(38sample)andii)produ edwithplant
ashassour eof ux(5 samples)-with theselatterprobably representingalater intrusionand not
belongingtotheoriginalgroupofmaterials. Thenatronglass anbefurtherdivided,onthebasis
of the on entration of Fe, Ti and Mn, inthe two main ompositional groups widespread in the
Mediterranean from the 4 th
entury onward: HIMT (24 samples) and Levantine I (14 samples)
[1℄. Amongthe HIMTsamples,we found both weak HIMT(14samples)and strong HIMT(7
samples)[2℄. The3 remaining samplesseem to forma newHIMTgroupshowing higher ironand
New developments in early industrial stained glasses
Forna elli C 1;2
,Turbanti MemmiI 1
1Department of EarthS ien e, University of Pisa, Italy; 2Department of Earth S ien e,
University of Siena,Italy; Forna elliunisi.it
Abstra t
In the present work, 50 samples of stained glass have been studied in order to dis lose the
im-provements inglassprodu tionintrodu ed afterthe growth ofindustry inthelate 18 th
andearly
19 th
enturies; the large s ale produ tion of glass and the development of new te hniques led to
a revivalof stainedglassmanufa ture, ulminated duringthelate 19 th
entury withthe addition
to thebat h ofmanynew olouring agents, or syntheti versions oftheoldones, and synthesized
rawmaterials (su h asSolvaypro essedsoda).
The sample repertory in ludes both transparent and opales ent glasses produ ed by some
Italian, German and Ameri an glassworks between the late 19 th
and the rst half of the 20 th
enturies. All samples have been preliminarily analyzed by SEM-EDS and XRF in order to
hara terize the bat h omposition and the olouring agents. XRD has been utilized as well
to identify rystallinephases employed asopa ifying agents.
Basedonmajorelement ontents,themajorityofsamples anbe onsideredassoda-lime-sili a
glasses, with few examples of mixed alkali-lime and lead-potash glasses. Con erning oloured
transparent glasses, the addition of new olouring agents synthesized during the 19 th
entury
su h as pure obalt (mainly used for blue tints), admium (yellow and orange), selenium (pink
and amber) and zin (asso iated with sulphur to produ e a deep red tint) has been on rmed.
Moreover, high ontents of al ium and uorine have been dete ted in all opales ent samples by
SEM-EDS and XRF (XRD analysis on rmed the presen e of uorite, CaF), while zir onium
(introdu ed as zir on, ZrSiO
4
or zir onium dioxide, ZrO
2
), has been dete ted as well in some
Glass orrosion: integration of experimentation and
modeling to develop a me hanisti understanding of
glass-water interfa ial rea tions
Pier e EM 1
1Environmental S ien e Division, Oak Ridge National Laboratory, Oak Ridge,TN. United
States; pier eemornl.gov
Abstra t
Glass-water interfa ial rea tions play a riti al role in the evolution of natural and engineered
systems(e.g., geologi repositories). Furthermore, thedesireto design durableglasses for various
industrial appli ationshas alsoresulted insigni ant interest inglass-water interfa ial rea tions.
For aluminosili ate and borosili ate glasses,one oftheexistings ienti hallenges is to de ipher
the omplex oupled rea tions ontrolling theformation, evolution, and transformation of
sili a-ri h surfa e layers. Sili a-ri h surfa e layers, similar to inorgani oatings on natural minerals,
an ae t the mi ros opi pro esses(e.g. , iondiusion, adsorption, et .) thatimpa t elemental
release rates. A urately des ribing the impa t of these layers on the glass hemi al durability
andlong-term orrosion behaviorrequiresamole ular levelunderstandingoftherates and
me h-anisms o urring at the glass-water interfa e. This presentation will highlight re ent advan es
in experimental approa hes and omputational models that are urrently being implemented to
Glass- erami materials for building and ballisti prote tion BaldiG 1 ,Pelli iL 1
1CE.RI.COL Colorobbia Resear h Centre; baldig olorobbia.it
Abstra t
In the eldof material s ien e there's an emerging interest for glass erami materials and their
appli ationsinbuildingsandballisti prote tion. Thebehaviourofthis lassofmaterials, bridging
a ross erami andglass, anleadto aseries ofinnovative produ tsvery promising intheviewof
ompetitiveness of Italian industry infront of aggressive ompetitors, espe iallyinAsia.
In the Colorobbia Italia resear h entre CERICOL we started more than 10 years ago with
an a tivity based on the development and industrialization of new glass erami materials. Due
to the use of nu leation and rystallization te hniques we have obtained omposite materials
with sub mi rometri or even nanometri rystalline textures, this led to opaque materials with
advan edme hani alandaestheti alfeaturesthat anbeusedinbuildingasar hite tural itemsor
interiorselements[1℄. Thehighme hani al modulusandhardnessdrovethedevelopmenta tivity
towardstheprodu tionofmaterialsforballisti prote tionwhilethe ontrolof rystallinesizeata
nanometri s aleledto theprodu tion ofaseriesoftransparentmaterials withimproved ballisti
andar hite tural features. Theindustrials ale-upallowstheprodu tionofsheet andotheritems
with dierent size and shape while advan ed de oration te hniques based on nanote hnology,
allowsthedevelopmentofsurfa esaestheti allyinnovativeandte hnologi ally advan ed. Theuse
ofnano-oxideandnano-metalsledtothedevelopment ofsmart surfa es[2℄asantiba terial,
self- leaningandanti-smog,givinganaddedvaluetotheseprodu tsintermsofsafenessandhealthiness
forthe onsumers. Ithasbeeninvestigatedthenu leationand rystallizationbehaviourofa
glass- erami materialintheLi
2 OAl 2 O 3 SiO 2
system,withinterestinitsopaque-transparentbehaviour
forbuildingandballisti prote tion,asso iatedtogoodme hani alstrength, surfa ehardnessand
low thermal expansion. The appli ation of nano TIO
2
and AgO nanostru tures on the surfa e
givesto the produ tsadvan ed hara teristi s asself- leaning,antiba terialand anti-smog.
Referen es
[1℄ BaldiGetal(2007),WO2007/088151.
Kineti s of iron redu tion in anhydrous pantelleriti glasses Stabile P 1 ,GiuliG 1 ,Ci oni MR 1 ,BehrensH 2 ,Knipping J 2 ,Paris E 1
1S hool of S ien e and Te hnology, Geology Division,University of Camerino (I);2Institute
of Mineralogy, LeibnizUniversity Hannover(D); paola.stabileuni am.it
Abstra t
Thekineti sofFeredu tioninpantelleriti meltshavebeeninvestigated bymeansof olorimetri
wet hemistryandFeK-edgeX-rayAbsorption NearEdge Spe tros opy(XANES).Sampleswith
a. 5 wt% Fe
2 O
3
have been synthesizedinair andre-melted inRe-boats inagasmixing furna e
(Ar/H
2 /H
2
O) under redu ing onditions (log fO
2
/bar: -13.90). Kineti experiments have been
performedat dierent melting times, rangingfrom 1hto 72 hours.
Theironspe iationratiointheseglasseswas he kedbya olorimetri wet hemistrymethod,
whi h on rmsthein rease of Fe 2+
/Fe
tot
inthesamples withtime. As shownbyMagnien et al.
[1℄,theevolutionofFe 2+
/Fe
tot
withtimeatagiventemperature anbereprodu edbyexpressions
of theform (F t F eq )=(F 0 F eq )exp( t= ): TheequilibriumFe 2+ /Fe tot
valueinoursets ofsamples rangesfrom89to 94%witharelative
un ertainty of 4%. At temperatures near1250 Æ
C, equilibrationtimes of 20 hours were found to
besu ient toa hieve the equilibriuminall theglasses.
XANES Pre-edge peak data learly indi atethat Fe 3+
isinfourfold oordination andits role
asanetworkformer is onsistent with previous works[2-5℄. Divalentiron displays anaverage
o-ordinationnumberintermediatebetween4and5. Onlysmalldieren eshavebeendete tedinthe
integratedareaofthepre-edge peaks forglasseshavingdierent K/(K+Na)ratio,indi atingthat
thein reasing oftheK/(K+Na) ratioprodu ed only smallvariations intheaverage oordination
numberof Fe for these ompositions.
Properties and stru tural role of iron in sili ate melts and glasses Tannou I 1;2 ,Jeroy M 1 ,de Ligny D 3 ,NeuvilleDR 2
1Saint-GobainRe her he, Fran e; 2Institut de Physique du Globe deParis, Fran e;
3Université Claude Bernard Lyon1, Fran e; tannouipgp.fr
Abstra t
Iron isan important element to probe the propertiesand thestru ture ofsili ate melts. Inearth
s ien e most of lava ontains more than 10% of iron whereas the proportion is mu h smaller in
industrialmaterials. Ironusually o ursintwo dierent valen e states(Fe 2+
orFe 3+
),and three
oordinations: 4,5and6. Thus, thein uen e ofironoxide onthemelt propertiesis ompli ated.
Consequently, the redoxratio of sili ate glasses and melts is an important parameter whi h role
mustbeproperly studied tounderstand thephysi al and hemi al properties ofthese materials.
The oordination of iron mayevolve asa fun tion of theredox state. These hanges are due
tothefa tthatironisessentiallypresent intheformofFe 3+
intetrahedralpositionatlower
tem-peratureswhereas itmainly o urs asFe 2+
in6-fold oordination at higher temperatures. These
hanges in the iron oordination may in uen e the short range order around network modi er,
su h asNaor Ca.
X-rayAbsorption Spe tros opyexperimentsareveryvaluableto determineshort-range order.
It shouldallow us to study the ironvalen e and oordination, aswell asthesodiumand al ium
environment. However this te hnique is not always a essible. Therefore, other experimental
methodsmustbeusedtostudythenetworkmodi ationssu hasRamanspe tros opyandele tron
mi roprobe.
Wefo usedour work onthe hangeswhi hhappen inthe glassduring thetransitionbetween
dierent redoxstates. Espe iallywithregard to the networkstru ture and thelo alenvironment
Sulfur in alkaline melts: An experimental study Ia ovino K 1 ,Giuli G 2 ,CarrollMR 2
1Dept. of Geography, Universityof Cambridge, England; 2S hool of S ien e andTe hnology
- Geology Division, Universityof Camerino (I); ki247 am.a .uk
Abstra t
We present preliminary results from experiments to establish the solubility and uid/melt
par-titioning of sulfur (sulfate and sul de) innatural alkaline melts (basanite, KI-04; and phonolite,
ERE-97018) from Erebus vol ano, Antar ti a. Melt omposition is known to strongly in uen e
S solubility in natural melts, parti ularly with respe t to FeO
total
and SiO
2
[1℄. Although melt
polymerizationisthoughtto haveasigni antee tonsulfursolubilityandspe iation,itislikely
thatanumberofotherfa tors,in ludingmeltalkaliandiron ontent,alsoplayarolein ontrolling
sulfur behaviorinmelts. Thisexperimental studyexaminestheinterplaybetween alkalis, oxygen
fuga ity,pressure,FeandSoxidationstate,andFeandS oordinationgeometriesandtheiree ts
on sulfateandsul de solubilityand uid/melt partitioning. Sulfur saturatedand undersaturated
experimentshave been arriedout overarangeofoxygenfuga ities(logfO
2
=-12to -6,ranging
from a. the iron-wustite buer to NNO+3.45), pressures of 1 bar and 1 kb and temperatures
above thesili ateliquids(1030and 1200 Æ
Cfor phonoliteandbasanite, respe tively). Thisrange
of experimental onditions and analyses of the sulfur ontents via ele tron mi roprobe and
sul-fur and iron spe iation and oordination geometry via XANES will allow sulfur solubility and
partitioningto be evaluatedwithrespe tto theabove listed experimental parameters.
Preliminary results indi ate a marked in rease intotal S solubility inevolved phonolite melt
relative to primitive basanite at similar T- fO
2
onditions. In addition, we have established the
ee t of fO
2
on the solubility of total S at 1 kbar in basanite KI-04 based on experimental run
produ ts ontaining sulfur-bearing rystal phases (i.e. sulfate, sul de). Experiments indi ate a
steep in rease inS solubilityat highly oxidizing onditions (fO
2
=NNO+1.53; 1000 ppm
dis-solved S) and minimum solubility at moderately oxidizing onditions (fO
2
= QFM+0.23; 200
ppmdissolved S). Thestrongly non-linear relationshipbetween S solubility and fO
2
has
impli a-tions for sulfur degassing at Erebus vol ano, whose erupted produ ts indi atea distin t de rease
inoxygen fuga ity during uid-magma as ent.
Future experimentsat higher pressure (1 GPa) andanalyses ofall experimental produ ts via
XANESwillelu idatethe rolesofoxygenfuga ity,pressure,FeandSoxidationstate,and Feand
Implementation of the Panum Crater dome (California).
Rheologi al study and diusion of water in the pumi e
and obsidian Floury P 1 ,Neuville DR 1 ,Le Losq C 1 ,Moretti R 2
1Institut dePhysique du Globe, Sorbonne Paris-Cité, Univ. Paris DiderotUMR-CNRS 7154,
Paris,Fran e; 2Istituto Nazionale di Geo si a e Vul anologia, Napoli, Italy; ouryipgp.fr
Abstra t
Despitethe ndingsofprevious studies,the in uen eofphysi o hemi al propertiesofmagmason
the onstru tionanddynami ofvol ani domesisnotfullyunderstood. Parti ularly,thevis osity
of magmas strongly in uen es the stru ture and stability of vol ani domes. This parameter
strongly depends on the temperature, the hemi al omposition, the volatile dissolve and the
bubbles ontent of magmas. With these onsiderations, it is important to understand volatile
behaviour wit h is a parameter of the rst order that will ontrol theeruptive dynami s. Water
is the most important volatile, whi h auses a drasti in uen e on the vis osity. Panum Crater
is the most re ent dome eruption at the hain of Mono Craters in the north of Long Valley
aldera (California). It is a dome omposed of obsidian and pumi e, whi h was established in
1350 AD [1℄. Least lava emissions ontain a great ontrast of dierent pumi es. Its stru ture
and morphology represent a parti ular interest and a simple obje t of study to understand the
relationship between the gasphaseand its implementation through thedynami eruption. Goals
are to measure diusion in the border around bubbles to understand the formation of the gas
phase. The pro les of water diusion to the walls of ea h type of bubble shows an opposite
pro ess: theri hpumi e waterdiuseswaterinobsidianwhilearound mi rometri bubbleswater
ontent de reases, approa hingthe bubbleimplying thatwater diuses into thebubble obsidian.
Therefore the dynami s behind these two pro les are dierent. In the ase of highly deformed
pumi e, itis possible thata generation of bubblesformed inmore depthin awater-ri h magmas
rise. These pro esses will therefore have impli ations for the understanding of the dynami s of
development ofthedome. Modellingofdiusionpro lesbyFi k'sse ondlawontheexperimental
datausedto onstrainseveralparameters onthe onditionsofformationofbubbles. Theseresults
allow better onstraining the parameters of the dynami establishment of Panum Crater and
potentiallyextendingthese results to otherdomes.
Referen es
Determining the provenan e of Mediterranean obsidian artifa ts Ferra uti P 1 ,Giuli G 1 ,Paris E 1 ,ContiP 1
1S hool of S ien e and Te hnology, Universityof Camerino(I); pierluigi.ferra utigmail. om
Abstra t
Providing a generally valid model to lassify and determine the provenan e of obsidian
ar haeo-logi alartifa tsoftheMediterraneanarea,wastheaimofthisresear h. Thishasbeen arriedout
toover omethea tualproblemofthewideun ertaintyarisingwhentryingtodistinguishsamples
fromsimilar,although separatesour esorto omparethemto literaturedata. Reported hemi al
analyses of obsidian are hara terized by being obtained with a variety of analyti al methods,
laboratories or sets of analyzed elements, introdu ing a major di ultywhen trying to usethese
datafor provenan e studiesofan ient artifa ts.
The development of a omprehensive statisti al method applied to take into onsideration
all the hemi al parameters hara teristi of ea h obsidian sour e has been arried out using
dierent statisti almethods,organizedinasequen e thatallows thedis rimination, stepbystep,
of all the sour es. The method is based on the building of a large hemi al database reporting
both geologi al and ar haeometri al literature obsidian data from the vol ani distri ts of the
Mediterranean - Aeolian, Pontine, Sardinian,Pantelleria, Carpathian and Aegean.
Asa rststep, omparisonofNormalProbabilityPlotsbetweendierentsour esand
interrela-tionsbetweenelementalabundan esallowedustoindividuatedis riminatingelementsandtra ers,
likeS ,Rb,Cs,Sr,Ba,Ta,Hf,Zr,Nb,Y,Th,UandREE.Thenmultivariatedataanalysisallowed
usto developee tivedis riminating models,usingPrin ipal Component Analysis(PCA),Linear
Dis riminant Analysis(LDA),Soft Independent Modeling ofClassAnalogy(SIMCA)and Partial
Least Squares Dis riminant Analysis (PLS-DA). The established pro edure allows to sele t the
dis riminating elements to be ompared withthe geologi al ngerprint of dierent sour es. The
pro edure, tested on both literature and new data, has theadvantage of making theprovenan e
study ofobsidianartifa ts independent fromtheanalyti al method usedaswell asfrom theneed
The amphoteri behavior of water in sili ate melts from
the point of view of their ioni -polymeri onstitution
MorettiR 1;2;3 ,LeLosq C 4 ,NeuvilleDR 4
1Dipartimento di Ingegneria Civile,Design. Edilizia e Ambiente, Se onda Università degli
Studidi Napoli,Aversa(CE), Italy; 2IstitutoNazionale di Geo si a e Vul anologia sezione
Osservatorio Vesuviano, Napoli,Italy; 3Department of Geology, St. Mary's University,
Halifax, Nova S otia, Canada; 4Institut dePhysique duGlobe, Sorbonne Paris-Cité, Univ.
Paris DiderotUMR-CNRS 7154, Paris, Fran e; roberto.morettiunina2.it
Abstra t
Disso iationof water into hydronium and hydroxyl ions is a fundamental feature of aqueous
so-lutions. Although it exerts a profound in uen e on properties of magmas, this autoprotolysis
rea tion has been hitherto negle ted for water dissolved in sili ate melts. As made here withan
a id-basemodel,one hasinfa ttodealwithmole ularwater(H
2 O
mol
)andtwokindsofhydroxyl
groups, bondedor nottonetwork-forming ations(OHand OH ,respe tively)inhydroussili ate
melts. Bymixing ationsandanionsondistin tsublatti esandquantifyingthedisproportionation
ofwaterdissolvedinsili atemeltsintoitsioni produ ts,H +
andOH ,were on ilespe tros opi
determinations ofwaterspe iation, and explainthe ontrasting rheology of hydrousbasalti and
rhyoliti melts. Infa tbasaltsshowmu hlessdepressionofvis ositybywateradditionbe auseof
a relativepredominan e of OH ,su h thatwater in reasetendsimmediately to limit
depolymer-izationrather thanenhan eit. Thisopensnewperspe tivesto theunderstandingofthe hemi al
ontrolleading to eithereusiveor explosiveeruptions. Inaddition,our modelmaybeapplied to
Rheologi al onstraints in welded pyro lasti alkaline
rhyolites: a ase study from Nuraxi Formation, SW
Sardinia, Italy TarragoM 1 ,GisbertG 2 ,Gar ia-VallesM 1 ,Gimeno G 2 ,MartinezS 1
1Dpt. de Cristallogra a, Mineralogiai Dipòsits Minerals, Universitatde Bar elona (Spain);
2Dpt. Geoquìmi a, Petrologia i Prospe iò Geològi a, Universitatde Bar elona (Spain);
ona.tarragogmail. om
Abstra t
Vis osityofpyro lasti owdepositshasastronginterestfor riskassessment invol ani hazards,
as an input variable for eruption modelling; and also in the interpretation of the empla ement
of an ient vol ani units. However, it is hampered by la k of an extense rheologi al database.
Data presentedhere hara terize theevolution ofvis osityina verti alpro le of theNuraxitu,
whi h an be of interest when studying the empla ement of the rest of nearly peralkaline and
peralkaline ignimbriti units in theSul is region. Petrographi al observations revealed omplete
devitri ationofthero k,butthe ompositionofformerglass,andbyextension,formermagmati
liquid,have been obtained by measuring hemi al omposition ofthematrix byEMPA.
Determination ofvis ositydependingontemperature wasattemptedon ylindri alro k ores,
powdered ro k,quen hed moltenro kand syntheti glassbymeans ofdilatometry and hot-stage
mi ros opy. The ee t of volatile ontents on vis osity was al ulated through numeri al
mod-elling [1℄,mainly basedin hemi al omposition. In addition to measured vis osity,petrographi
analysiswasperformedinordertoestablisharelationshipbetween realvis osity,deformationand
devitri ation. Analysesondrymaterials determined thatdeformation startedwell over 1100 Æ
C
(higher than natural temperatures ofrhyoliti ows). However, vis osityde reased sharplywhen
volatiles were taken into a ount. An amount around 1-2 wt %of water would redu e vis osity
under108 Pas insidethe 700 - 850 Æ
Crange, thus enabling therhyoliti glassto ow.
Referen es
Spherulites in tra hyti melts Arzilli F 1 ,VoltoliniM 2 ,Man ini L 1 ,Ci oni MR 3 ,Giuli G 3 ,Carroll MR 3
1Elettra-Sin rotrone Trieste S.C.p.A.,S.S. 14, Km163, 5 in Area S ien e Park, 34012
Basovizza, Trieste, Italy; 2Lawren e BerkeleyNational Laboratory, Cy lotron Rd, 94720
Berkeley, California,USA; 3S hool of S ien e andTe hnology Geology Division,University
of Camerino, Italy; fabio.arzillielettra.trieste.it
Abstra t
Spherulites are luster of radiating rystals that o ur ommonly inrhyoliti melts underhighly
non-equilibrium onditions [1-2℄. Textural dataon spherulitesof alkali-feldspar and pyroxeneare
showninthisstudy. Spherulites grewintra hyti meltsduring oolingandde ompression
exper-imentswithwater-saturated onditions. Theaim of thiswork isto better understand thegrowth
of spherulites as a fun tion of under ooling (T), P
H
2 O
, time and superheating. Experiments
were arried out using Cold Seal Pressure Vessel apparatus at pressure range of 30 200 MPa,
temperature range of 750 850 Æ
Cand duration of 2 16 hours. This study presents
prelimi-nary quantitative data on spheruliti morphologiesobtained both byele tron mi ros opy (SEM)
andphase- ontrast syn hrotron X-raymi rotomography. Be auseexperimentswereperformedat
dierent experimentaldurations, theevolution of spherulites anbe studied and furthermore the
rystallographi misorientation, the hanges insize andthe aspe tratio anbe measured.
Three kinds of spherulites o ured during our experiments: (i) spherulites hara terized by
widely spa ed rystals arranged radially around the nu leus, in agreement with previous
obser-vations [3-4℄; (ii) spherulites hara terized by a i ular and tiny bers radially aggregated; (iii)
spherulites hara terized by the transition from a single rystalinto a poly rystalline spherulite
(denselybran hedspheruliti morphology). Thepreliminaryresultsaboutalkalifeldsparspherulites
show that their growth rate is about 10 7
m/s. Spherulites were grown between 100 and 200
MPa, thus at highwater ontents. Moreover, low T alongwithlarge superheating an enhan e
the nu leation and growth of spherulites. Therefore, low T, large superheating and high P
f
onditions an triggerthe rystallization ofspheruliti morphologies.
Referen es
[1℄ WatkinsJ. etal(2008),Contrib. Mineral. Petrol. 157,163-172.
[2℄ GraànàsyL.etal(2005),Phys. Rev. 72,011605.
[3℄ Keith,H. D.and Padden F. J.(1963), J.Appl. Phys. 8,2409-2421.
V lo al environment in phosphate glasses Benzi F 1 ,GiuliG 1 ,Della Longa S 2 ,Paris E 1 ,SiligardiC 3
1S hool of S ien e andTe hnology - Geology Division, University of Camerino(I);
2Dipartimento di Medi ina Sperimentale, Università dell' Aquila (I);3Department of
Engineering EnzoFerrari, Universityof Modena and Reggio Emilia(I);
federi o.benziuni am.it
Abstra t
Glasses ontaining vanadium nd appli ations in a variety of s ienti and te hnologi al elds
like sensors, atalysis, ele troni devi es and glass erami s. The valen e state of V depends on
the oxygen fuga ity, thus vanadium in glasses is redox sensitive and an be used as an oxygen
barometer [1℄. Syntheti glasses ontaining V oxides have been widely studied be ause of their
pe uliarpolaroni semi ondu tivebehavior[2℄. However,thestru turalroleofvanadiuminglasses
isnot ompletely understood,yet.
X-ray absorption spe tros opy (XAS) in the near edge (XANES) part of the spe trum is
proposed to study the V lo al environment (oxidation state, oordination geometry and bond
distan es)in two glasses: VPNa10 (starting omposition10 % V
2 O 5 - 45 %P 2 O 5 - 45 %Na 2 O)
and VPNa80(starting omposition 80 %V
2 O 5 - 10 %P 2 O 5 - 10 %Na 2
O). The pre-edge feature
ofaXANESspe trumisa ngerprint ofthe oordinationgeometryand valen e state[3,4,5℄. The
omparison between the pre-edge peak of a set of standards with known stru ture and the two
unknownglasses allowus to obtain qualitativeinformations on theVlo al geometry andvalen e
of the glasses: VPNa10is mainly 4+ in 5-fold oordination and VPNa80 is mainly 5+ in 5-fold
oordination.
Sin e thepre-edge featurealone isnotableto giveafullquantitativeinformation about bond
distan e and oordination distortion, ab-initio modeling for the ontinuum part of the XANES
spe trum is shown using the MXAN pro edure [6℄. Cal ulations performed for the model
om-poundsareingoodagreementwiththeexperimentalspe tra. Thisstepallowusto builda
frame-work tostudy inaquantitative waythe V lo alstru tureof theglasses. Preliminary al ulations
areshown forthetwo glasses.
Natural sili ate glasses from the deep rust BartoliO 1 ,Cesare B 1 ,A osta-Vigil A 2 ,Ferrero S 1;3
1Departmentof Geos ien es, University of Padua, Fran e; 2Instituto Andaluz deCien ias
de la Tierra, CSIC, Univ. Granada, Spain;3Institut fürErdund Umweltwissens haften,
UniversitätPotsdam, Germany; omar.bartoliunipd.it
Abstra t
Small (20 m) droplets of graniti melt produ ed by partial melting (anatexis) of the deep
metasedimentary rust an be en losed by minerals (perite ti phases) growing during melting
rea tions [1-3℄. These datarepositories maysurvive,shielded bythehost, during thesubsequent
P-T-thistory ofthero k,and mayprovide ompositionalinformation(major andtra e elements,
andvolatile ontents)on natural rustalmelts otherwiseimpossible toretrieve [4,5℄. Insome
ex- eptionalgeologi al ontexts(e.g.,theNeogeneVol ani Provin eofSESpain;LaGalite,Tunisia),
fragmentsof thepartially melted rust maybe rapidlybrought tothe Earth'ssurfa e bymagma
uprise, and quen hed from temperatures of . 800-900 Æ
C. This allows the preservation of the
melt as glass [2, 4℄. However, the oexisten e of totally rystallized in lusions (nanogranites)
along with preserved glassy in lusions in more onventional, slowly ooled, anate ti ro ks su h
asmigmatites andgranulites, isageologi al oddity. Despite the omparable ompositions,glassy
andnanogranitein lusionsappeartohavedierentsizedistributionsinkhondalites(SIndia),
sug-gestingthatthenu leationwasinhibitedinthesmallerin lusions[1℄. Theporesizeee tseemsto
ndlesseviden einRondamigmatites(SSpain), wherethesizeofglassyin lusionsisoftenequal
to, and sometimes even larger than, that of the nanogranites, suggesting that additional fa tors
(e.g.,impurities within the in lusions or surfa e irregularities)may signi antly ae t nu leation
kineti s.
Referen es
[1℄ CesareB. etal. (2009),Geology,37,627-630.
[2℄ CesareB. etal. (2011),J.Virt. Expl.,38, paper2.
[3℄ Ferrero S.etal. (2012),J. Met. Geol, 30,303-322.
[4℄ A osta-Vigil A. etal. (2010),J.Pet.,51,785-821.
Ar haeometri study of samples glass from the
Ciutadella de Roses site (Empordà, Girona), NE Spain
Gar ia-Valles M 1 ,PuigAM 2 ,Gimeno D 3 ,AulinasM 1
1Dpt. Cristallogra a, Mineralogiai Dip. Minerals, Fa . Geologia,Universitat deBar elona
(UB), /o Martí i Franquès,s/n, 08028 Bar elona (Spain); 2Arqueóloga- onservadora ,
Ajuntament de Roses. Avda. deRhode, s/n, 17480 Roses (Spain); 3Dpt.Geoquimi a,
Petrologiai Prospe ió Geològi a, Fa . Geologia,Universitatde Bar elona, /o Martí iFranquès,
s/n, 08028 Bar elona (Spain); d.gimeno.torrentegmail. om
Abstra t
The ar haeologi al ex avations ondu ted in renaissan efort area of theCiutadella of Roses (15
kmnorthofthe greek-roman ityof Emporium)have showntherestsoftheGreek ityofRhode,
founded at 776 B.C. by Rhodianpeople; the Hellenisti quartier (espe ially important at IV-III
enturiesB.C.;aromanvilla(o upiedbetween enturiesIIB.C.andVID.C.);aromain-lombard
monastery (XI entury), and a series of rests till XIX entury. A number of 25 samples were
hosenand leanedinorderto hara terize itsmain hemistrybyEMPA.Themajor onstituents
Si, Al, Na, K, Fe, Mn, Ca, Mg, Ti and P were analyzed, as well asa number of tra e elements
(metals) that give indi ation on the olour of glass: Co, Cu, Cr, Sb and Pb. The ar haeologi al
dataallow dating the on erned strata inseveral periods: end of VI entury-beginning of VII (3
samples) and from middle XVI entury to XVIII entury. All the studied glass fragments show
asodi -lime omposition, beingtheones orrespondingto VI-VIIoflowmagnesia andpotassium
ontent(andthereforeofromantraditionandprodu edwithnatron)nearin omposition(butnot
exa tlyidenti al)to the LevantineI group ofromanglass(i.e. whenplotted ina CaOvs Al
2 O
3
diagram). The rest of the glass an be interpreted as the produ t of fusion of sili a sands with
a ux of vegetal origin (ash of halophyti plants, widespread in the marsh se tor of Roses bay.
Althoughmostoftheglassfragmentsareun olored,twoglassfragmentsofblueandgreenish-blue
olortakethispigmentationduetothepresen eoflittleamountsof obalt. Anothergreenish-blue
olour glassfragment isdue to the oexisten e ofhigh ontents ofiron and opper(a well-known
Glasses ontaining opper slag for erami glazes MugoniC 1 ,VeronesiP 1 ,Siligardi C 1 ,Remigio V 2
1Departmentof Engineering EnzoFerrari; 2Cerami a FondovalleSpA, Maranello, Italy;
onsuelo.mugoniunimore.it
Abstra t
Largequantities ofwastematerialssu has opperslagareprodu ed asaby-produ tofindustrial
operations. Theextra tionof opperfromsulphideoresisusually arriedout withina
pyrometal-lurgi al pro ess route, whi hinvolves themininga tivitiesand on entration ofthe oreoftenvia
otation followed by smelting and re ning operations to produ e pure opper metal [1℄. During
smelting, an oxide-ri h phase knownas slag forms and issegregated from the opper-matte
(sul-phide) phase. Disposal of su h large quantities of opper slag often presents waste management
problems sin e opper slag is lassi ed ashazardous materials be ause it ontains heavy metals.
The aim of the present work is the reuse and valorization of opper slag as glazed oatings for
erami substrates. The opper slag was previously hara terized in terms of X-ray dira tion
(XRD), X-Ray uores en e analysis (XRF), parti le size distribution and hot stage mi ros opy
(HSM). TheXRF resultsshowthat theslag is hara terized by signi ant levelsof ironzin and
sili on, whilethe XRDpatterns suggestthatthe powder is vitreouswithsome rystalline peaks.
Finallythe HSM ofthepowder reveals toohighT
sphere andT
hemisphere
;whi hmake itnot useful
for thesele ted erami appli ation. For this reason,the slag powder wasmixed withtwo
dier-ent waste glasses and sodium arbonate in order to promote the de rease of the temperature of
interest and to fa ilitate themelting onditions. The bat hes were mixed, melted and quen hed
inwater to obtainfrits. The frits,whi h exhibited lower T
sphere ,T hemisphere and T ow ,were used
to prepare glazes for erami tile oatings. The nal glazes were hara terized by means X-ray
dira tion(XRD),Color Hunter parameter (L,a,b) and hemi al properties.
Referen es
[1℄ DavenportW.G.L.etal. (2002), Extra tive Metallurgyof Copper, Pergamon Press,Oxford.
A knowledgements
Authors would like to thank LIFE Program for nan ial support in the framework of proje t
Alumina/alumina La-glass omposites for dental prostheti appli ations Siligardi C 1 ,Mugoni C 1 ,DisoD 2 ,Li iulli A 3
1Department of Engineering Enzo Ferrari, University of Modena andReggio Emilia, Via
Vignolese905, 41100 Modena, Italy; 2Salente srl, Via dell'Eser ito 8, Cavallino,Le e, Italy;
3Department of Engineering for Innovation,Universityof Salento,Via per Monteroni 73100
Le e, Italy; ristina.siligardiunimore.it
Abstra t
Thepresentworkisfo usedonthedevelopmentofglassfritsoptimizedforthein ltrationofporous
Al
2 O
3
ompositepreforms. Chopped berinaluminaglass omposites werepreviouslydeveloped
as innovative material for all erami dental prostheti solutions su h us rowns, bridges, and
xed partialdentures. The pro ess wasee tive for obtaining dense, strong, netshape erami s.
Glass ompositions belongingto lanthanumsili ateborate systems(namedLa-glasses) havebeen
onsidered and synthesized to reinfor e and onfer an aestheti appearan e. Through a Design
of Experiments (DoE) approa h, fteen formulations of dierent raw materials (input fa tors)
were produ ed using a mixture design. The formulations were melted and quen hed in water
at room temperature to obtain the frits. The frits that showed lower T
ow
were used for the
glass in ltration of Al 2 O 3 to obtain Al 2 O 3
/La-glass samples. The frits were dispersed in water
and applied as a slip on the surfa e of Al
2 O
3
porous surfa e. The slip oated spe imens were
heated from room temperature to 1200 Æ
C. During this thermal pro ess the La glassfrits melts
anddiusesfromthesurfa edeepinsidethealumina omposite. Thefritsandtheglassin ltrated
sampleswere hara terizedthroughX-Raydira tion(XRD),dierentialthermalanalysis(DTA),
hotstagemi ros ope(HSM),ColorHunterparameters(L,a,b),ands anningele tronmi ros opy
(SEM).The owtemperatures(T
ow
),obtained fromtheHSM,andtheLparameter valueswere
analyzed by statisti al methods to obtain two models, whi h des ribe the relationships between
the formulation fa tors and these two properties of interest. The frit omposition along with
thesintering parameters plays animportant role to a hieve zero porosity,and onsequently good
me hani al properties. Thegeneration of ompressiveresidual stresson thesurfa e,improves the
me hani al properties of the erami s. Eventually it will seal and oppose to ne surfa e ra ks
A osta-Vigil A,27 Amalberti J,8 Arletti R,14 ArzilliF, 25 AulinasM, 28 BaldiG, 17 Bartoli O, 27 BehrensH,18 Benzi F, 26 Burnard P, 8 CarrollMR,20,25 Cesare B,27 Cestelli-GuidiM, 9 ChinniT, 14 Ci oni MR,3,9,18,25 Conte S,14 Conti P,22 de LignyD,19 DellaLonga S,26 Dingwell DB, 1,3 DisoD,30 Ertel-Ingris hW, 3 Fal one R,11 Ferra uti P,22 Ferrero S,27 Floury P,21 Forna elli C, 15 Gar ia-Valles M, 24,28 Gimeno D,7,24,28 GiordanoD, 1 Gisbert G,24 Giuli G, 3,9,18,20,22,25,26 GlatzelP,9 Hess KU, 1 Ia ovino K,20 Jahn S,13 JeroyM, 19 KnippingJ, 18 Koeberl C, 5,9 Kvashnina K,9 Laporte D,8 Le LosqC, 21,23 Li iulliA, 30 Man ini L,25 MartinezS,24 Milke R,12 MorettiR,4,21,23 MugoniC, 29,30 NeuvilleDR,2,19, 21,23 Paris E, 3,9,18, 22,26 Pelli i L,17 Pier e EM, 16 PratesiG, 9 PuigAM,28 RemigioV,29 RussellJK, 1 SiligardiC, 26,29,30 StabileP,18 Takada A,10 Tannou I, 19 Tarrago M, 24 Turbanti MemmiI, 15 VandiniM, 14 VeronesiP, 29 Voltolini M, 25
