Pressure-temperature-fluid constraints for the Emmaville-Torrington emerald deposit, New South Wales, Australia: Fluid inclusion and stable isotope studies

Abstract

The Emmaville-Torrington emeralds were first discovered in 1890 in quartz veins hosted within a Permian metasedimentary sequence, consisting of meta-siltstones, slates and quartzites intruded by pegmatite and aplite veins from the Moule Granite. The emerald deposit genesis is consistent with a typical granite-related emerald vein system. Emeralds from these veins display colour zonation alternating between emerald and clear beryl. Two fluid inclusion types are identified: three-phase (brine+vapour+halite) and two-phase (vapour+liquid) fluid inclusions. Fluid inclusion studies indicate the emeralds were precipitated from saline fluids ranging from approximately 33 mass percent NaCl equivalent. Formational pressures and temperatures of 350 to 400 °C and approximately 150 to 250 bars were derived from fluid inclusion and petrographic studies that also indicate emerald and beryl precipitation respectively from the liquid and vapour portions of a two-phase (boiling) system. The distinct colour zonations observed in the emerald from these deposits is the first recorded emerald locality which shows evidence of colour variation as a function of boiling. The primary three-phase and primary two-phase FITs are consistent with alternating chromium-rich ‘striped’ colour banding. Alternating emerald zones with colourless beryl are due to chromium and vanadium partitioning in the liquid portion of the boiling system. The chemical variations observed at Emmaville-Torrington are similar to other colour zoned emeralds from other localities worldwide likely precipitated from a boiling system as well.

Full text

Cent. Eur. J. Geosci. • 4(2) • 2012 • 287-299
DOI: 10.2478/s13533-011-0056-9
Central European Journal of Geosciences
Pressure-temperature-fluid constraints for the
Emmaville-Torrington emerald deposit, New South
Wales, Australia: Fluid inclusion and stable isotope
studies
Research Article
Lara Loughrey1, Dan Marshall1∗, Peter Jones2, Paul Millsteed3, Arthur Main4
1 Earth Sciences, Simon Fraser University,
Burnaby, BC, V5A 1S6, Canada
2 Earth Sciences, Carleton University,
Ottawa, ON, K1S 5B6, Canada
3 Earth Sciences Research School,
Australia National University,
Canberra, ACT, Australia
4 Canberra Lapidary Club,
Lyons, ACT, Australia
Received 29 October 2011; accepted 3 February 2012
Abstract: The Emmaville-Torrington emeralds were first discovered in 1890 in quartz veins hosted within a Permian
metasedimentary sequence, consisting of meta-siltstones, slates and quartzites intruded by pegmatite and aplite
veins from the Moule Granite. The emerald deposit genesis is consistent with a typical granite-related emerald
vein system. Emeralds from these veins display colour zonation alternating between emerald and clear beryl.
Two fluid inclusion types are identified: three-phase (brine+vapour+halite) and two-phase (vapour+liquid) fluid
inclusions. Fluid inclusion studies indicate the emeralds were precipitated from saline fluids ranging from ap-
proximately 33 mass percent NaCl equivalent. Formational pressures and temperatures of 350 to 400 ◦C and
approximately 150 to 250 bars were derived from fluid inclusion and petrographic studies that also indicate emer-
ald and beryl precipitation respectively from the liquid and vapour portions of a two-phase (boiling) system. The
distinct colour zonations observed in the emerald from these deposits is the first recorded emerald locality which
shows evidence of colour variation as a function of boiling. The primary three-phase and primary two-phase FITs
are consistent with alternating chromium-rich ‘striped’ colour banding. Alternating emerald zones with colourless
beryl are due to chromium and vanadium partitioning in the liquid portion of the boiling system. The chemical vari-
ations observed at Emmaville-Torrington are similar to other colour zoned emeralds from other localities worldwide
likely precipitated from a boiling system as well.
Keywords: Fluid Inclusions • Australia • Boiling • Emerald • Element Partitioning
©Versita sp. z o.o.
∗E-mail:marshall@sfu.ca 287

Pressure-temperature-fluid constraints for the Emmaville-Torrington emerald deposit, New South Wales, Australia
1. Introduction
TheEmmavilleemeraldoccurrencewasthefirstfinancial
viableemeraldproducerinAustraliadiscoveredcloseto
thesmalltinminingtownofEmmavilleinnorth-eastern
NewSouthWales(Figure1). Miningoperationsduring
theperiodof1890and1908resultedin 28000 carats
ofemeraldbeingmined[1,2]. From1908to1963,pe-
riodicminingoccurred;however,during1963and1964,
unknownquantitiesofgood qualityemeraldsandberyl
wererecovered[1,3].Muchofthematerialextractedfrom
theminewastoopaleincolourandonlyasmallamount
wasofvalue.Theoveralllowqualityandthedifficultsep-
arationofthegemundamagedfromitshardmatrixpre-
cludedanyfinancialviability. Themajorityofemeralds
foundwereunder1caratinweight,withthelargeststone
weighing60 carats (however, containing severalimper-
fections)[1,2,4]. Detailsofthecompletemininghistory
oftheareahavebeendescribedbyMumme,andBrown.
Duringtheearly1990s, asmalldepositofemeralds,of
quitesurprisingquality,wasdiscoveredinawelldecom-
posedpegmatitelocatedunderanunsealedroadnearTor-
rington,aformertinminingvillagelocatedapproximately
10km eastofEmmaville’shistoric EmeraldMine. The
emeraldfromthislocalitydisplayedyellow-greencolours
andwerealsosufficientlytransparent. Thelargeststone
thatwasextractedfromthemineweighed73caratsand
wasa flawless,yellow-greencolour [4]. Miningopera-
tionswereconductedundergreatsecrecyatTorrington,
andthediscoveryisnowconsideredexhausted.
2. Geologic Setting
TheEmmaville occurrence is situatedin thePaleozoic
NewEnglandfoldbelt[1,5],ineasternAustralia. The
NewEnglandfoldbeltcontainsthreestructuralelements,
consistingoftwofoldandthrustbeltsontheeasternand
westernsideofagraniticbatholith. Twotectonizedser-
pentine belts represent the contact zones between the
graniteandthefoldandthrustbelts.Theultramaficrocks
wouldbethemostlikelyhostforemerald;however,the
emeraldinthislocalityishostedwithinaPermiansed-
imentary sequence, consisting of siltstones, slates and
quartzites, intruded by pegmatite and aplite from the
nearbyMouleGranite(Figure1),whichcomprisespart
of a larger granitic batholith within the New England
foldbelt. Theintrusionofthepegmatites occursalong
north-easttosouth-westjointsystems[1].Anirregularly
shaped lode dips in a north-east to south-west direc-
tionattheEmeraldMinefromtheMoulegranitestock.
This emerald-bearing lode consists of a quartz, topaz,
feldsparandmicapegmatite,andrangesfrom50mmto
1mwidths. Accordingto[1],theemeraldsoccurirregu-
larly,as‘bunches’,in thepegmatite. Theyarecommonly
stronglyembedded in cavitiesandoften surrounded by
dickiteinthequartz-topazveinrock. Othermineralsas-
sociatedwithemeraldsinthelodearecassiterite,fluo-
rite,arsenopyrite, wolframite, huebnerite, ferberite, and
quartz[1]. IntheTorringtonlocality,emeraldwasrecov-
ered from theHeffernan’sWolfram mine, approximately
5kmnorthwestofthetownofTorringtonand40kmnorth
ofEmmaville(Figure1)[5]. Theemeraldoccursinade-
composedpegmatitelodeabout30cmwidewithvugsof
quartz,feldspar,biotite,andwolframite.
3. Emerald Composition
The emerald crystals from these deposits are strongly
colourzonedparalleltothebasalpinacoid(0001),andto
alesserextentparalleltothehexagonalprism(1010)[6].
Colourzoningissostronglydevelopedthattheseemer-
alds consist of alternating bands of green to greenish
yellowemerald andcolourlessberyl (Figure 2). These
bandsvaryinthicknessfromseveralmicrometerstosev-
eralmillimetersandtheboundariesbetweentheemerald
andcolourlessberylaregenerallysharpandcontinuous.
Electronmicroprobeanalyseswereconductedalongset
traversesperpendiculartothegrowth zones(Figure3).
Usingbackscatteredelectron(BSE),theoxideconcentra-
tionsforCr,V,andFeareshowninanelectronmicroprobe
traverseacross a numberofgrowthzones. Thefinely-
layeredgrowthzonesperpendiculartothec-axisofthe
crystalareclearlydelineatedinthebackscatteredimages,
wherethedarkbandscorrespondtocolourlessberyl,and
thelighterbandscorrelatetothegreenbandsofemerald.
ThereisagoodagreementbetweenCrandVconcentra-
tionwitharelativelypoorcorrelationbetweentheseel-
ementsandFe. Overall,theemeraldfromtheEmmaville
occurrenceischromiumdominant,withthecolourzones
intheemeraldcrystalsupportingchemicalvariationsthat
resultintheobservedcolourlessberylandgreenemerald
zones.SincesubstitutionoccursattheYsiteinthecrystal
structureofberyl,thevariationsincolourareattributedto
complicatedsubstitutionsatthissiteand/orslightvaria-
tionsinfluidcomposition,withvaluesofCr2O3,V2O3,and
Fe2O3,rangingupto 0.59, 0.13, 0.33masspercentre-
spectively.TheconcentrationsofFe,Cr,andVhavebeen
plottedrelativetoemeraldanalysesworldwide(Figure4).
Thereisaslightdifferencebetweentheelementalconcen-
trationsfromthisstudyandpastdata[1,7–9]. However
sinceemeraldfromthesedepositsisquitezonedandvari-
288

L. Loughrey, D. Marshall, P. Jones, P. Millsteed, A. Main
Figure 1. Geologic map of the Emmaville area, showing the two localities of emerald formation; the Emerald Mine and Emerald & Wolfram Mine
(modified from [2], [5]).
Figure 2. Zoned emerald from the Emmaville deposit showing good
colour and clarity. Colour zonations are parallel to the
basal pinacoid and alternate between green (emerald) and
colourless beryl with variable growth zone thickness.
ableinchemicalcomposition,itislikelythatthevariation
betweenourdataandtheliteraturedatareflectsdeposit
scalevariationinthemajorchromophores,chromiumand
vanadium. Themorechromium-richzonesofthecrystal
areplottedindarkandthecolourlessberyl inlighton
Figure4. Itiseasilyidentifiablethattheconcentrations
ofCrhaveresultedinthisspreadinthedata. Notably,
thedepositshowssomeoverlapwithdepositsinMada-
gascar,Pakistan,Colombia,andotherAustralianemerald
inthePoonaregionandatMenzies,bothinWesternAus-
tralia. SelectedcationconcentrationsrelativetoAland
Mg+Mn+FerespectivelyareplottedasFigures5and6.
Thereisadifferencebetweenthecolourzonationshigh-
lightedby the cationconcentrationsversus Al, as sub-
stitutionoccursatthissitewithvaryingcompositionsof
Figure 3. Microprobe mass percent oxide data for selected oxides in
emerald along two traverses (labelled Line 1 and Line 2).
The photomicrograph is a backscatter image of the emer-
ald crystal. The thick black semi-horizontal line indicates
the position of the electron microprobe chemical traverse
with analysis points spaced equidistantly from left to right
and corresponding to analyses 1 to 27 (Table 1; Line 1).
The dark bands in BSE correspond to colourless beryl,
and the lighter bands correlate to the green bands of emer-
ald.
chromiumandvanadium. ThevaluesforMgOandNa2O
areextremelylowfortheEmmavilleandTorringtonemer-
aldsandmaybeconsideredasanadditionalcharacteristic
propertyofthedeposit.Thesevaluesarequitesimilarto
theByrudemeralddepositinNorwayandemeraldsfrom
Delbegetey,Kazakhstan[9,10].
Cathodeluminescence(CL)studies(Figure7)wereused
tocomplementtheBSEimagery. CLshowsgreaterde-
tailwithintheemeraldcrystalwiththelightbandscorre-
spondingtothesamelightbandsinBSEandtherefore,is
indicativeofhigherCrandVrichzonesoremeraldbands 289

Pressure-temperature-fluid constraints for the Emmaville-Torrington emerald deposit, New South Wales, Australia
Figure 4. Ternary FeO-Cr2O3-V2O3(mass %) plots of Emmaville-Torrington emerald compositions (dark and light grey plus signs) superimposed
on the worldwide emerald compositions from literature data compiled in [9]. Data are normalized from mass percent microprobe analyses
(Table 1), with Fe data reported as FeO.
Figure 5. Al versus the sum of other Y-site cations, in atoms per formula unit. The Emmaville-Torrington compositions (dark and light grey plus
signs) are superimposed on worldwide emerald data compiled from the literature in [9].
Figure 6. Mg+Mn+Fe versus monovalent channel-site cations, in atoms per formula unit. The Emmaville-Torrington compositions (dark and light
grey plus signs) are superimposed on worldwide emerald data compiled from the literature in [9].
290

L. Loughrey, D. Marshall, P. Jones, P. Millsteed, A. Main
Table 1. Electron microprobe compositions of the Emmaville-Torrington emerald along traverse (Line) 1.
Analysis# 1 2 3 4 5 6 7 8 9 10 11 12 13 14
SiO2(mass%) 67.31 66.58 66.70 67.17 66.97 66.96 67.24 67.11 67.32 66.78 66.75 67.36 67.09 67.56
TiO20.00 0.01 0.01 0.00 0.00 0.01 0.00 0.00 0.02 0.00 0.00 0.00 0.01 0.00
Al2O318.70 18.93 18.66 18.87 18.72 18.75 18.73 18.42 18.41 18.37 18.40 18.60 18.85 18.78
Sc2O30.00 0.00 0.01 0.01 0.00 0.01 0.02 0.01 0.02 0.02 0.03 0.01 0.01 0.02
V2O30.01 0.03 0.04 0.04 0.01 0.05 0.04 0.12 0.17 0.17 0.17 0.06 0.06 0.03
Cr2O30.24 0.09 0.25 0.12 0.09 0.10 0.25 0.56 0.50 0.53 0.46 0.40 0.13 0.21
MgO 0.05 0.01 0.03 0.03 0.03 0.03 0.02 0.04 0.02 0.05 0.01 0.03 0.04 0.05
CaO 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.01 0.00 0.00 0.01
MnO 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
FeO 0.19 0.20 0.17 0.22 0.24 0.20 0.23 0.25 0.20 0.22 0.23 0.21 0.23 0.24
CoO 0.00 0.00 0.00 0.01 0.01 0.02 0.01 0.00 0.00 0.01 0.01 0.01 0.00 0.01
Na2O 0.02 0.02 0.04 0.03 0.04 0.03 0.05 0.03 0.04 0.07 0.03 0.04 0.05 0.03
K2O 0.00 0.01 0.01 0.01 0.01 0.00 0.00 0.01 0.01 0.00 0.00 0.00 0.01 0.02
Analysis# 15 16 17 18 19 20 21 22 23 24 25 26 27
SiO2(mass%) 66.75 67.06 67.68 67.64 67.11 67.40 67.30 66.89 67.30 67.22 67.10 67.39 66.81
TiO20.00 0.01 0.00 0.00 0.02 0.00 0.00 0.00 0.00 0.01 0.00 0.01 0.00
Al2O318.71 19.01 18.85 19.09 19.04 19.10 19.09 18.92 18.57 18.71 18.90 18.83 18.71
Sc2O30.02 0.01 0.01 0.00 0.01 0.01 0.02 0.02 0.02 0.02 0.00 0.02 0.03
V2O30.04 0.05 0.03 0.04 0.02 0.02 0.02 0.03 0.10 0.02 0.00 0.04 0.05
Cr2O30.11 0.15 0.17 0.12 0.04 0.02 0.04 0.06 0.38 0.06 0.08 0.16 0.20
MgO 0.05 0.04 0.03 0.04 0.03 0.03 0.04 0.03 0.04 0.04 0.04 0.05 0.05
CaO 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00
MnO 0.00 0.01 0.00 0.02 0.00 0.01 0.00 0.00 0.00 0.01 0.00 0.00 0.00
FeO 0.21 0.19 0.18 0.22 0.16 0.22 0.19 0.18 0.17 0.18 0.17 0.22 0.22
CoO 0.01 0.01 0.01 0.01 0.02 0.02 0.01 0.01 0.01 0.01 0.01 0.00 0.00
Na2O 0.05 0.05 0.05 0.05 0.05 0.06 0.08 0.05 0.05 0.06 0.05 0.08 0.08
K2O 0.00 0.01 0.01 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.01 0.01
Allanalysesarecalculatedbasedon18oxygenand3beryllium.
Table 1. (continued) Electron microprobe compositions of the Emmaville-Torrington emerald along traverse (Line) 2.
Analysis# 1757 1789 1820 1852 1883 1915 1947 1978 2010 2041 2073 2105 2136 2168 2199 2231
SiO2(mass%) 66.30 66.51 66.36 66.59 66.51 66.12 66.84 67.15 66.47 66.26 66.32 66.48 66.72 66.77 66.72 66.47
TiO20.00 0.00 0.00 0.01 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00
Al2O318.45 18.55 18.53 18.45 18.57 18.63 18.64 18.85 18.51 18.65 18.69 18.79 18.64 18.69 18.76 18.81
Sc2O30.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00
V2O30.03 0.03 0.03 0.03 0.01 0.02 0.04 0.00 0.02 0.00 0.02 0.00 0.02 0.00 0.01 0.00
Cr2O30.33 0.39 0.55 0.42 0.40 0.18 0.31 0.09 0.46 0.25 0.29 0.24 0.21 0.21 0.19 0.10
MgO 0.04 0.04 0.02 0.04 0.03 0.03 0.03 0.03 0.03 0.04 0.03 0.04 0.03 0.03 0.03 0.04
CaO 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00
MnO 0.01 0.03 0.00 0.01 0.02 0.00 0.04 0.00 0.02 0.00 0.03 0.01 0.01 0.03 0.04 0.01
FeO 0.19 0.16 0.18 0.16 0.16 0.23 0.16 0.17 0.19 0.17 0.19 0.22 0.19 0.26 0.20 0.23
CoO 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Na2O 0.06 0.06 0.06 0.06 0.06 0.06 0.05 0.06 0.06 0.06 0.06 0.07 0.05 0.06 0.07 0.04
K2O 0.02 0.01 0.01 0.03 0.04 0.00 0.02 0.01 0.02 0.03 0.02 0.01 0.02 0.02 0.02 0.01
Analysis# 2263 2294 2326 2357 2389 2421 2452 2484 2515 2547 2579 2610 2642 2673 2705
SiO2(mass%) 66.33 66.47 67.32 66.90 67.04 67.28 67.09 66.77 67.07 67.09 66.96 67.09 66.88 67.17 66.88
TiO20.00 0.00 0.01 0.00 0.00 0.00 0.01 0.00 0.00 0.01 0.00 0.02 0.00 0.00 0.00
Al2O318.75 18.65 18.87 18.79 18.74 18.83 18.47 18.53 18.38 18.61 18.80 18.45 18.89 18.93 18.96
Sc2O30.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
V2O30.01 0.01 0.00 0.00 0.02 0.01 0.00 0.02 0.04 0.02 0.00 0.01 0.03 0.03 0.00
Cr2O30.07 0.12 0.11 0.22 0.30 0.28 0.22 0.49 0.42 0.34 0.29 0.42 0.02 0.02 0.01
MgO 0.03 0.04 0.02 0.03 0.02 0.03 0.03 0.03 0.03 0.04 0.02 0.03 0.04 0.04 0.04
CaO 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00
MnO 0.00 0.00 0.01 0.03 0.00 0.02 0.01 0.00 0.02 0.01 0.01 0.02 0.00 0.04 0.01
FeO 0.22 0.21 0.19 0.23 0.15 0.16 0.15 0.22 0.16 0.19 0.16 0.24 0.15 0.20 0.24
CoO 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Na2O 0.07 0.06 0.06 0.06 0.06 0.06 0.05 0.04 0.06 0.07 0.06 0.07 0.07 0.06 0.06
K2O 0.03 0.01 0.01 0.01 0.00 0.03 0.01 0.00 0.03 0.02 0.01 0.02 0.01 0.02 0.03
Allanalysesarecalculatedbasedon18oxygenand3beryllium. 291

Pressure-temperature-fluid constraints for the Emmaville-Torrington emerald deposit, New South Wales, Australia
Figure 7. Photomicrographs of backscatter electron image ver-
sus cathode luminescence image of the emerald crystal.
Good correlation between light coloured (CL and BSE)
and coloured beryl/emerald zones. Central zoning in cen-
tre of image indicates emerald precipitation, dissolution
and subsequent reprecipitation of the more parallel outer
growth zones. The intersectorial zoning is also referred to
as Brazilian twinning.
inthe crystal. It is evident that thereis finergrowth
zoneswithinwhatwereoriginallylargergrowthzonesin
BSEimaging.Minorchemicaldifferenceswithinthesame
growthzonesarealsoobserved. Lastly,disruptedzoning
andirregularlyshapedzonesindicateemeraldprecipita-
tion, dissolution andsubsequent re-precipitation of the
moreparalleloutergrowthzones.Braziliantwinning[11]
isalsoobservedintheemeraldcrystal(Figure7)showing
intersectorialzoning,whichcouldalsobeduetochemical
starvationduringquickgrowthofthecrystal.
4. Fluid Inclusions
FluidinclusionsstudiesontheEmmavilleemeraldsidenti-
fiedtwodominantFluidInclusionTypes(FITs).Thefirstis
atwo-phase(vapour+brine)assemblage.ThesecondFIT
iscomposedofthree-phase(brine+vapour+halite±solid)
fluidinclusions.Thefluidinclusionsinthesamplesstud-
iedoccurasplanesofinclusionsalonghealedfractures,
growthzonesorasisolatedinclusions.Thereisanabun-
danceof growth zones observed in thezoned emerald,
anditwaspossibletoconclusivelyidentifyprimaryfluid
inclusionsfrombothFITs,basedontimingrelationships
betweenfluidinclusionsandmineralgrowthcharacteris-
tics[12–14].BothFITswerealsoidentifiedaspseudosec-
ondaryinclusionscuttinggrowthzones,indicatingapro-
tractedoccurrence ofbothFITsduring emerald growth.
Thetwo-phaseFITcomprisesinclusionsconsistingofa
brine and vapour bubble. The dominant phase is the
gaseousphase that occupies approximately 85%of the
fluidinclusionvolume,whereastheaqueousbrinerepre-
sentstheremaining15%ofthevolume,atroomtempera-
ture.Theinclusionsdisplayconsistentphaseproportions,
generally,andrangeupto210micronsinsize.Thesec-
ondobservedFITconsistsofthree-phaseinclusionswitha
brine,vapourbubble,halitecube. Additionallyrarebire-
fringentmineralsareobserved. Astheyarenotconsis-
tentlypresentinallinclusionsanddonotdissolveduring
heating,theycanbeconsideredasaccidentallytrapped
solids. Themainphaseinthethree-phaseinclusionsis
theaqueousbrinethatconstitutesapproximately45%of
thefluidinclusionvolume,with30%volumeinthevapour
phaseandremaining25%volumehalitecube.Thesefluid
inclusionscanrangeupto80micronsinsize,anddisplay
consistentphase proportions. The growthzonesinthe
emeraldareeasilyidentifiableintransmittedlightandde-
finedbybothFITsinthesamplestudied(Figure8).Thus
bothFITsareconsideredtobecontemporaneouswiththe
emeraldformationbasedonpetrographicrelationshipsof
thefluidinclusionsandthegrowthzones.
Fluidinclusionswithinquartzcoexistingwiththeemer-
alddisplayconsistentfluidcompositionstotheFIAsob-
servedwithinthezoned emeraldcrystals. Thelack of
growthzoneswithinthequartzprecludedtheidentifica-
tionofprimaryfluidinclusionswithinthequartz,thusthis
studyconcentratedonfluidinclusionsthatcouldbeun-
equivocallypetrographicallyrelatedtothecolourzonation
withinemerald.
4.1. Microthermometry
Rapidcoolingof theprimarytwo-phasefluidinclusions
from room temperature, results in thenucleation of ice
atapproximately-55◦C.Uponfurthercoolingto-160◦C,
nootherphasechangeswereobserved. Heatingthein-
clusionsfromthistemperatureresultedinthefirstmelt-
ingoficeover thetemperaturerange-30.3to -21.7◦C.
Thisrangeineutectictemperatures wouldindicatean-
othergasor chloridespeciesispresentinthefluidin-
clusions. Nocompressiblegasesweredetectedandthus
wedeemitmorelikelythatthereareadditionalchlo-
ridespeciespresent.Furtherheatingresultedinthefinal
icemelt temperatures which rangefrom-6.5to-2.5◦C.
Heatingtheinclusionsfromroomtemperatureresultedin
marginalincreasesinthesizeofthevapourbubbles. As
thevapourbubbleexpandedtowardstheedgeofthein-
clusionsitobscuredthefinalhomogenisationofthefluid
inclusionsandthusthehomogenizationtemperatures(Ta-
ble2)weredeterminedbasedonthelastremainingvisible
portionsoftheliquidpriortothemeniscusbeingtotally
obscuredbythefluidinclusionwalls[14].
Uponrapidcoolingfromroomtemperatureto-180◦C,the
three-phaseFITnucleatediceovertherange-50and-
30◦C.Heatingtoroomtemperatureresultedinfinalice
meltingtemperaturesovertherange-30to-20◦C.Heat-
292

L. Loughrey, D. Marshall, P. Jones, P. Millsteed, A. Main
Figure 8. Photomicrograph of an assemblage of (a) primary two-
phase fluid inclusions occurring within and parallel to
banding/growth zones in colourless beryl (brl), (b) pseu-
dosecondary three-phase fluid inclusions occurring along
a healed fracture in colourless beryl, (c) primary three-
phase fluid inclusions occurring within and parallel to
banding/growth zones in emerald (em). In addition to the
halite cube, a vapour bubble and a halite saturated liquid
defines this assemblage for this fluid inclusion population.
Some inclusions also contain a rare accidental birefringent
(biref) mineral inclusion. Photos taken in plane polarised
light.
Table 2. Microthermometric measurements on the fluid inclusions
from emerald at Emmaville-Torrington.
Chip/Flinc# eutectic Tmice Tmhal Thvap Notes
EmTorr-01-1-1 -21.7 -2.5 Primary
-2 -26.1 -3.8 Primary
-3 nv -4.0 Primary
-4 nv -3.4 Primary
-5 -25.7 -2.9 Primary
-6 -23.2 -3.0 Primary
-7 nv -5.8 Primary
-8 -30.3 -6.5 Primary
-9 nv -4.2 Primary
-10 -24.5 -4.2 Primary
-11 nv -4.3 Primary
-12 nv -3.9 Primary
-13 nv -4.0 Primary
-14 nv -3.2 Primary
-15 nv -2.9 Primary
-16 nv -3.1 Primary
-17 nv -3.6 Primary
-18 -28.5 -5.5 Primary
-19 -25.6 -5.6 Primary
-20 nv -6.1 Primary
EmTorr-01-2-1 nv 218.9 >400 Pseudosecondary
-2 nv 217.4 >400 Pseudosecondary
-3 nv 220.2 >400 Pseudosecondary
-4 nv 222.5 >400 Pseudosecondary
-5 nv 225.1 >400 Pseudosecondary
-6 nv 219.4 >400 Pseudosecondary
-7 nv 221.8 >400 Pseudosecondary
-8 nv 221.4 >400 Pseudosecondary
-9 nv 223.4 >400 Pseudosecondary
-10 nv 221.4 >400 Pseudosecondary
-11 nv 219.8 >400 Pseudosecondary
-12 nv 227.1 >400 Pseudosecondary
-13 nv 222.7 >400 Pseudosecondary
-14 nv 227.1 >400 Primary
-15 nv 230.5 409.1 Primary
-16 nv 225.8 >400 Primary
-17 nv 223 >400 Primary
-18 nv 226.3 367.4 Primary
-19 nv 225.1 >400 Primary
-20 nv 224.5 370.4 Primary
-21 nv 230.1 >400 Primary
-22 nv 218.9 >400 Primary
-23 nv 231.4 >400 Primary
-24 nv 228.4 >400 Primary
-25 nv 226.8 >400 Primary
-26 nv 226.2 >400 Primary
-27 nv 208.9 >400 Primary
-28 nv 212.4 >400 Primary
-29 nv 224.5 >400 Primary
-30 nv 220.1 >400 Primary
All temperatures reported in degrees Celsius, eutectic=ice melting eu-
tectictemperature, Tmice=Ice melting temperature,Tm ha=halitemelt-
ing/dissolution temperature, Th vap=vapour homogenization temperature
intotheliquid,nv=notvisible.
293

Pressure-temperature-fluid constraints for the Emmaville-Torrington emerald deposit, New South Wales, Australia
Figure 9. Histogram of halite melting microthermometric data for the
Emmaville-Torrington three-phase fluid inclusions.
ingtheinclusionsfromroomtemperaturesresultedinthe
volumeofboth the vapour bubble and halite cubede-
creasinguntilfinalhomogenizationintotheliquidphase.
Thesetemperaturesrangedfrom209◦Cto231◦Cforthe
halitedissolution(Liquid+Halite→Liquid)and367◦C
to409◦Cforthevapourbubblehomogenisation(Liquid+
Vapour→Liquid).Thehalitemeltingtemperaturesmea-
suredinthethree-phaseinclusionscorrespondtoarange
ofsalinitiesfrom32.2to33.6masspercentNaClequiva-
lentanddefineanormaldistribution(Figure9). Dueto
fluidinclusionstretching,decrepitation,anddamage,ho-
mogenizationtemperaturesarefalselyelevatedandtem-
peraturesinexcessof400◦Cwerenotmeasured,andthe
finalvapourhomogenizationtotheliquidphasecouldnot
bedetermined precisely in some inclusions. The most
commoncaseofpost-entrapmentvolumechangeswithin
ourfluidinclusions isstretching. Thiswasdocumented
bycomparingphotographs,takenatroomtemperature,of
vapourbubblevolumewithinaninclusionpriortoandafter
heatingruns.Ifthevolumeofthevapourbubbleincreased
thiswasinterpretedasstretchingofthefluidinclusion.
Fortunately,not allinclusionswithin the FITstretched
andwewereabletoestimatefluidinclusionmolarvolumes
fromtheunstretchedinclusions,asheatingbeyond400◦C
mightriskstretchingordecrepitatingotherfluidinclusions
withinthesample. Forthepurposesofthestudy,inclu-
sionsshowingfalselyelevatedhomogenisationtempera-
turesduetostretchingoranyevidenceofpost-entrapment
changeswerenotusedforpressure-temperaturedetermi-
nations.
Therarebirefringentphasespresentalongsidetotheliq-
uid,vapourandhalitedidnotmeltuponheatingandare
thereforeclassifiedasaccidentallytrappedsolids. Due
Table 3. Stable isotope data .
Samplenumber δ18OH
2OδD
/Mineral (,SMOW) channel(mass%)(,SMOW)
LL11-02-1beryl 11.1 0.7 -79
LL11-02-2beryl 10.8 0.7 -103
LL11-02-3beryl 12.4 0.6 -96
LL11-02-4beryl 11.4 0.8 -100
LL11-02-4quartz 9.7
tothesmallsizeoftheseaccidentalinclusionsandsub-
optimal optics within the inclusions, it was difficult to
identifywhatisthenatureofthesemineralsinthethree-
phase FITs. Raman spectroscopy was unsuccessful in
identifyingtheaccidentaltrappedsolidsduetothehigh
backgroundfluorescenceofthehostemerald.
5. Stable Isotopes
Berylcrystallisesinthehexagonalsystemandisstruc-
tured with interconnected six-membered rings of silica
tetrahedra producing channels that parallel the c-axis.
Thechannelsaccommodatearangeofaqueousfluidsand
dissolvedcationsthatmaintainchargebalancewithinthe
beryl. Thefluidstrappedwithinthechannelcontribute
minimallytotheoverallδ18Ooftheberylhostbutcon-
taintheonlyhydrogenasmolecularH2Owithintheberyl
structureandrepresenttheoriginalformationalfluidin
equilibriumwiththeberylduringcrystallization[15].Ex-
tractionandtrappingofthechannelfluidsabove800◦C
andsubsequentδDanalyseshavebeenusedinconjunc-
tionwithδ18O analysesof theberyltodistinguishbe-
tweendifferentemeralddeposits, determinefluidsource
anddeposittype[16]. Hydrogenandoxygenstableiso-
toperatiosfromemeraldchannelfluidsatEmmaville(Ta-
ble3)yieldδ18Ovaluesrangingfrom10.8to12.4%¸and
δDvalues from -79to-103%¸relative to VSMOWin-
ternationalstandard. These values are consistent with
the δ18O-δD signature of highly evolved peraluminous
graniticrocks withcontribution from sedimentary rocks
(Figure10).
Thelimitedδ18OV−SMOW dataforquartzandberyl(Ta-
ble3)yieldquartz-berylfractionationvaluesfortheEm-
mavilleemeraldoccurrenceinexcessofgeologicallyfea-
sibletemperaturesusingtheempiricallyderivedequation
of[19].Thesehightemperaturesmayberelatedtovaria-
tionsintheemeraldduetocolourzonationandaredis-
cussedbelow.
294

L. Loughrey, D. Marshall, P. Jones, P. Millsteed, A. Main
Figure 10. Channel δDH
2O versus δ18O for the Emmaville-Torrington emerald (stars; grey stars from [9] superimposed upon data from a number
of world localities compiled in the literature by [9,16]. The isotopic compositional fields are from [17] including the extended (Cornubian)
magmatic water box (grey). MWL=Meteoric Water Line, SMOW=standard mean ocean water.
6. Pressure Temperature Con-
straints
Halitemelting temperatures correspond to salinitiesof
approximately33masspercentNaClequivalent. Anide-
alizedfluidinclusionisoplethic sectionwasconstructed
baseduponthree-phaseFITfinalhomogenizationtemper-
aturesintotheliquidandcorrespondingsalinities[20,21].
Sincetherearetwoco-existingfluidphasespresentinthe
emeraldfrom Emmaville-Torrington,thepressure of en-
trapmentcanbedeterminedfromthemeasuredhomogeni-
sationtemperaturesandsalinities. Therelativelyconsis-
tentphaseratiosand lack of observed halite-dominant
three-phaseFITsuggeststhemajorityoftheEmmaville-
Torringtonthree-phaseFITwerelikelytrappedinaone-
phaseorliquidonlystabilityfieldfora33masspercent
NaClsolution(Figure11).Similarly,fromfluidinclusion
andpetrographicobservations,itcanbededucedthatthe
two-phaseFITsweretrappedpredominantlyinthevapour
onlystabilityfield(Figure11).Experimentaldataforthe
NaCl-H2Osystemareconsistentwiththevapourphase
ofa 33 mass percent NaClsystemcontainingvirtually
noNaCl. An astutereaderwill notice thatourvapour
richfluidinclusionscontainupto5masspercentNaCl.
Thusweinterpretourvapourdominantfluidinclusionsas
representingatrappedmixtureofpredominantlyvapour
andsomeresidualsalinebrine. Thisisalsoconsistent
withtheslightlyelevated homogenisation temperatures
recordedfor our vapour richfluidinclusionsoverthose
observedinthethreephasefluidinclusions. Liquidiand
iso-Th linesfortheH2O-NaClinclusionshaving30and
40masspercentsalinitiesofNaCl[22]wereusedtoin-
terpolatethe33masspercentisoplethusedforthisstudy.
Frommicrothermometry,thetemperatureconditionsrang-
ingfrom367◦Cand409◦Careusedinrelationtohalite
melttemperaturestodeterminethepressureofentrapment
ofco-existingvapourandliquidphasesoftheboilingsys-
tem.Anaveragehomogenisationtemperatureof380◦Cfor
a33masspercentNaClsolutionwasplottedusingdata
from[23] and [24] in PXspace (Figure 11). Similarly
thelowsalinityvapour-richfluidinclusionshostedinthe
clearberylbandsofthezonedemeraldcrystals,ploton
thevapourrichsideofthe380◦Csolvusinfigure11.This
stronglysuggeststhatthetwoFITsrepresentconjugate
fluidsofaboilingsystem,andwedeemthistheonlygeo-
logicallyreasonablescenariotoexplainthefluidinclusion
data. Thesefluid inclusion microthermometric observa-
tionsandsubsequentinterpretationsresultinbeingable
toplacesomeconstraintsontheemeraldformationbased
onboilingofthesystemtoapproximatetemperaturesof
greaterthan367◦Candpressuresover150bars.
295

Pressure-temperature-fluid constraints for the Emmaville-Torrington emerald deposit, New South Wales, Australia
Figure 11. Pressure-Mass % NaCl plot of solvi at 380, 500, 600◦C,
and various phase stability fields for an aqueous-saline
system. The liquid rich portions of the Liquid-Vapour
(L+V) solvi and the positions of the Liquid-Vapour-Halite
(L+V+H) curve are from [23]. The halite saturated
vapour curve (V+H) and the vapour rich portions of the
L+V solvi are from [24]. The conjugate vapour and liq-
uid compositions that best approximate the Emmaville-
Torrington fluid compositions at 33 mass percent NaCl
are shown as dashed lines.
7. Discussion
ThemajorityofemeraldsworldwideareformedbyaBe-
richfluidinteractingwithasourceofCr(±V).Acommon
classificationscheme foremeralddeposits aresplitbe-
tweenaType1depositrelatedtoagraniticintrusionand
Type2depositscontrolledbytectonicstructures[25,26].
Mostemeralddepositsfallinthefirstcategoryandare
subdividedon the presenceorabsence of schistatthe
contactzone.Type2depositsaresubdividedintoschists
withoutpegmatitesandblackshaleswithveinsandbrec-
cias[25,26].TheEmmaville-Torringtonemeraldsarecat-
egorizedasaType1deposit,whereassurroundingrocks
aremetasedimentsratherthanschists.Themostcommon
exampleofemeraldsderivingCrandVchromophoricma-
terialfromsedimentsaretheworld’slargestandrichest
emeralddepositsatMuzo,Colombia[27,28]. However,
thegeologicalenvironmentatEmmavilleandTorrington
ismoresimilartotheByrudemeralddepositinNorway.
Thesetwodepositssharemanycharacteristics: (1)con-
tainlowconcentrationsofNa2OandMgO,(2)formedin
pegmatitesillswhichintrudealumshale,(3)associated
mineralsincludequartz,feldspars,micas,fluorite,topaz,
cassiterite,wolframite,andarsenopyrite,(4)strongcolour
zonationsparalleltothebasalplane and (5) presence
ofboth vapour-dominateand halitebearingfluid inclu-
sions[29,30]. Themaindifferencebetween thetwois
theEmmavilledepositcontainsmorechromiumthanvana-
dium(<0.1mass%V2O3)(Figure4)andByrudhasminor
amountsofCH4inthefluidinclusions[30].Notably,sim-
ilaremeraldbandingisalsoobservedfromtheemeralds
inNamibia,specificallyfromtheErongoMountainsand
LeydsdorpinSouthAfrica[31].
TheformationoftheobservedcolourbandsatEmmaville
andTorringtonarerelatedtotheactivityofchromiumpar-
titioningintheliquidphaseoftheboilingsystem.During
thegrowthofthiscrystal,thetwophaseFITsconsistent
withthe colourlessberylzones representperiodswhen
the beryl wasdeposited from avapour, when theL+V
interfacedropped, and theareapreviouslyoccupied by
theliquidportionofthesystemwouldbepredominantly
withinthevapourfield(Figure12A)oftheboilingsystem.
Thethree-phaseFITsfoundwithinthegreenzonesofthe
crystalrepresent conditionswherethe liquidportionof
theboilingsystemprecipitatedemerald,andresultedin
thetrappingofliquid-richthree-phaseFIT(Figure12B).
Astheseinclusionsweretrappedconsistentlywithinthe
chromium-rich(oremerald)zones,thiswouldindicatean
increasedactivityofCrandVwithintheliquidportionof
thisboilingsystem.
Our petrographic observations of fluid inclusion com-
positionshostedwithinquartzarealsoconsistentwith
ourproposedmodelof boilingbeingthe mechanismfor
thecolourzonationwithintheEmmavilleandTorrington
emerald,butthelackofgrowthzoneswithinthequartz
limitanyapplicabilityofanymicrothermometricmeasure-
mentsofthequartzhostedfluidinclusionsbeyondthe
generalpetrographicobservationthat thequartzhosted
fluidinclusioncompositionsrepresentpotentialmixtures
ofarangeofthetwoendmemberfluidinclusionpopula-
tionsobservedintheemerald.
Thatfluid inclusionsaretrapped inboththeclear and
theemeraldgrowthzoneofthe crystal and that these
zonesarepetrographicallyrelatedtothevapour-richand
liquid-richportionsofaboilingsystem,wouldindicated
thatbothfluidsweresaturatedwithrespecttoberyleven
atrelativelylowtemperatures.Studies[32]athighertem-
peraturesareconsistentwithberylsaturationinmeltand
fluidinclusions,andourobservationsareconsistentwith
berylsaturationtotemperaturesaslowas350◦Cinboth
theliquidandvapourportionsofaboilingsalinebrine.
Limited sample material and δ18O emerald and quartz
analysesfromtheEmmavilledepositprecludesadetailed
discussion of the excessive temperatures obtained from
quartz-beryloxygenisotopethermometry. However,the
detailed fluid inclusion and emerald chemistry on the
zonationwithin these emeraldswouldindicate that the
emeraldbandswithinthestudiedcrystalswereprecipi-
tatedfromtheliquidportionofaboilingsystemandthat
296

L. Loughrey, D. Marshall, P. Jones, P. Millsteed, A. Main
Figure 12. Schematic representation of co-existing liquid and
vapour phases in a saline fluid within a vein/fracture sys-
tem. A) represents conditions where a beryl (white)
growth zone in the upper portion of the vein is precip-
itating from the vapour phase and an emerald (grey)
growth zone is precipitating from the liquid phase in the
lower portion of the vein. B) Schematic representation
of the case where the liquid-vapour interface has risen
within the vein system, and now an emerald (dark grey)
growth zone is precipitating on both crystals. As the
liquid-vapour interface within the vein system ascends
and descends, the crystals will have new growth zones
of emerald or colourless beryl being precipitated, de-
pending upon whether precipitation occurs from the liq-
uid or vapour respectively.
theclearzoneswhereprecipitatedfromthevapourportion
oftheboilingsystem. Thegrainandsamplesizeforthe
δ18Oemeraldanalysesislimitedtoafewsmallgrainsand
thegrainsaretoosmall/thintodeterminecolourandthus
zoning.Wepostulatethattherangeinδ18Ovaluesforthe
emerald(δ18O)maybeduetomixturesofgreen(emerald)
andclearberyl. Thisissuemayberesolvableviaδ18O
analysesemployingasecondarymassspectrometerbutis
beyondthecurrentscopeofthisstudy. TheδDanaly-
seswereperformedonamuchlargeramountofsample
materialandthus thechannelfluidsextractedprobably
representanaverageofthefluidstrappedinbothclear
andgreenzones,andthesedataarethusmoreapplicable
todepositgenesis(Figure10).
8. Conclusions
TheEmmaville-Torrington emerald deposits are Type1
emeralddeposits,withmetasedimentsatthecontactzone.
Thissedimentarysequenceisthesourceofchromiumand
vanadiumwhichinteractswiththeberylliumsuppliedby
thepegmatitesandaplitesofthe MouleGranite. Stable
isotopechannelwatersfromtheemeraldsampleconfirms
genesisfromdominantlymagmaticfluidswithminorcon-
tributionfromsedimentarysource(s).Thedistinctemerald
bandingobservedisduetoemerald/berylgrowthinthe
liquidandvapourportions,respectively,ofaboilingsys-
tem.Stableisotopesarelikelyconsistentwithinindivid-
ualgrowthbands,andinconsistentacrossthealternating
growthzones. Theemeraldzoningisinterpreted tobe
duetovariationsofaliquid-vapourinterfaceinaboiling
systemunlikemanyemeralddeposits whose consistent
coloursarelikelythe resultofprecipitation fromaho-
mogeneousfluidphase. Microprobeanalysesdetermined
thatincreasesinchromiumandvanadiumcontentareob-
servedintheemeraldzonesofthecrystal. Furthermore,
thereis a good correlation between BSEand cathode
luminescenceimageswithincreasedchromiumandvana-
diumcontent. Thefluidinclusionstudiesprovidedinfor-
mationofthecomposition,andminimumtemperatureand
pressureconditionsofgreaterthan367◦Candpressures
over150barsfora33percentmasssaline fluid. Both
FITsareconsideredtobecontemporaneouswiththeberyl
precipitationbasedonpetrographicrelationshipsbetween
growthzones and fluid inclusions. These twofluidin-
clusionpopulationsrepresentconjugatesofatwo-phase
boilingsystem,withtheslightlyelevatedsalinitiesinthe
vapourrichfluidinclusionsresultingfromminormixingof
avapour-dominantfluidwithresidualsalinebrineadher-
ingtocrystalsorleakingfromnearbyfracturesinthewall
rock. Fromthepetrographicworkandmicrothermometry
itisproposedthatberylsaturatedandprecipitatedboth
intheliquidandvapourstabilityfields. However,Cr,V
andFeenrichmentwasintheliquidportionoftheboiling
systemandtheemeraldbandsprobablyprecipitatedfrom
theliquidportionsoftheboilingsystem. Otheremerald
depositsworldwide that displayemeraldbanding, have
likelyexperiencedasimilarmodelofformationcompara-
bletotheEmmavilleandTorringtondeposits.
Acknowledgements
TheisotopicworkbyKerryKlassenofQFIRStableIso-
tope Lab at Queen‘s University is gratefully acknowl-
edged. NSERCfundingtoDMandLLisalsogratefully
acknowledged. 297

Pressure-temperature-fluid constraints for the Emmaville-Torrington emerald deposit, New South Wales, Australia
References
[1]Brown,G.,Australia’sfirstemeralds.JournalofGem-
mologyandProceedingsoftheGemmologicalAsso-
ciationofGreatBritain,1984,19,320-335.
[2]Mumme,I.A.,TheEmerald: ItsOccurrence,Discrim-
inationandValuation.PortHacking,MummePubli-
cations,1982,66-68.
[3]Mumme,I.A.,ModesofoccurrenceofemeraldsinAus-
tralia.TheAustralianGemmologist,1986,106-108.
[4]MacNevin,A.A.,Emerald—NewSouthWales.Aus-
tralasianInstituteofMiningandMerallurgy,1976,
8,311.
[5] Kazmi, A.H.and Snee, L.W., Geologyof the world
emerald deposits: a brief review, A.H. Kazmi,L.W.
Snee,Editors,EmeraldsofPakistan,VanNostrand
Reinhold,NewYork,1989,165–228.
[6]Pearson, G., Torrington Emerald. The Australian
Gemmologist,18,47-49.
[7]Schwarz, D., Australian Emeralds. The Australian
Gemmologist,1991,17,487-542.
[8]Schmetzer,K.,TorringtonEmeraldUpdate.TheAus-
tralianGemmologist,1994,18,318-319.
[9]Groat,L.A.,Giuliani,G.,Marshall,D.D.andTurner,
D.,Emeralddepositsandoccurrences:Areview.Ore
GeologyReviews,2008,34,87-112.
[10]Gravilenko, E.V., Calvo, P.B., Castroviejo, B.R. and
GarciadelAmo,D.,EmeraldsfromtheDelbegetey
deposit(Kazakhstan): Mineralogicalcharacteristics
andfluid-inclusion study. Mineralogical Magazine,
2006,70,159-173.
[11]Ramseyer, K. and Müllis, J., Geologic applica-
tion of cathodoluminescence of silicates. In M.
Pagel, V. Barbin, P. Blanc, and D. Ohnenstet-
ter, Eds., Cathodoluminescence in Geosciences,
Springer-Verlag,Berlin,2000,177–191.
[12]Bodnar,R.J.,Introductiontofluidinclusions,inSam-
son,I.,Anderson,A.andMarshall,D.,eds.,FluidIn-
clusions:Analysisandinterpretation: ShortCourse.
MineralogicalAssociationofCanada,2003a,32,1-8.
[13]Goldstein,R.H.andReynolds,T.J.,Systematicsof
fluid inclusions in diagenetic minerals. Society for
Sedimentary Geology, SEPM ShortCourse, 1994,
31,199.
[14]Roedder,E.,FluidInclusions,ReviewsinMineralogy:
MineralogicalSocietyofAmerica,1984,v.12,644p.
[15]Taylor,R.P.,Fallick,A.E.andBreaks,F.W.,Volatile
evolution in Archean rare-element granitic peg-
matites:Evidencefromthehydrogen-isotopiccompo-
sitionofchannelH2Oinberyl.TheCanadianMiner-
alogist,1992,30,877-893.
[16]Giuliani, G., France-Lanord, C., Zimmerman, J.L.,
Cheilletz, A., Arboleda, C., Charoy, B., Coget,
P.,Fontan,F.andGiard,D.,Fluidcomposition,δDof
channelH2Oandδ18Oof latticeoxygeninberyls:
Genetic implications for Brazilian, Colombian, and
Afghanistaniemeralddeposits.InternationalGeology
Review,1997,39,400-424.
[17]GiulianiG.,France-Lanord,P.Coget,D.Schwarz,A.
Cheilletz,Y.Branquet,D.Giard,A.Martin-Izard,P.
AlexandrovandD.H.Piat, Oxygenisotopesystem-
aticsofemerald:relevanceofitsoriginandgeologi-
calsignificance.MineraliumDeposita,1998,31,513–
519.
[18]Sheppard,S.M.F.,Characterisationandisotopicvari-
ationsin natural waters. in Valley,J.W., Taylor Jr.,
H.P.,O’Neil,J.R.,eds.,StableIsotopesinHighTem-
peratureGeologicalProcesses.ReviewsinMineral-
ogy,1986,16,165–183.
[19]Xue,G.Marshall,D.,Zhang,S.,Ullrich,T.,Bishop,
T.Groat,L.,Thorkelson,D.,Giuliani,G.andFallick,
A.,ConditionsforEarlyCretaceousemeraldformation
atDyakou,China: FluidInclusion,Ar-Ar,andstable
isotopestudies.EconomicGeology,2010,105,375-
394.
[20]Knight,C.L.andBodnar,R.J.,Syntheticfluidinclu-
sions:IX.CriticalPVTXpropertiesofNaCl-H2Oso-
lutions.GeochimicaCosmochimicaActa,1989,53,3-
8.
[21]Bakker,R.J.,PackageFLUIDS1.Computerprograms
foranalysisoffluidinclusiondataandformodelling
bulkfluidproperties.ChemicalGeology, 2003,194,
3-23.
[22]Bodnar,R.J.,Introductiontoaqueous-electrolytefluid
inclusions,inSamson,I.,Anderson,A.andMarshall,
D., eds., Fluid Inclusions: Analysis and interpre-
tation: ShortCourse. Mineralogical Association of
Canada,2003b,32,81-100.
[23]Atkinson, A.B., A model for thePTX properties of
H2O-NaCl.MScthesis,VirginiaPolytechnicInstitute
andStateUniversity,USA,2002.
[24]Sourirajan,S.andKennedy,G.C.,ThesystemH2O-
NaClatelevatedtemperaturesandpressures.Amer-
icanJournalofScience,1962,260,115-141.
[25]Schwarz,D.andGiuliani,G.,Emeralddeposits–A
review.TheAustralianGemmologist,2001,21,17-23.
[26]Schwarz,D.,Giuliani,G.Grundmann,G.andGlas,M.
DieEntstehungderSmaragde,einvieldisskutiertes
Thema,ExtraLapis,in: D.Schwarz,R.Hochleitner,
Editors,Smaragd,derkostbarsteBeryll,derteuerste
Edelstein,2001,68–73.
[27]Giuliani,G.,Cheilletz, A.,Arboleda, C.,Carrillo,V.,
Rueda,F.,Baker,J.H.,Anevaporiticoriginofthepar-
298

L. Loughrey, D. Marshall, P. Jones, P. Millsteed, A. Main
entbrinesofColombianemeralds:fluidinclusionand
sulphurisotopicevidence.EuropeanJournalofMin-
eralogy,1995,7,151-165.
[28]Ottaway,T.L.,Wicks,F.J.,Bryndzia,L.T.,Keyser,T.K.,
Spooner,E.T.C.,FormationoftheMuzohydrothermal
emeralddepositinColombia.Nature,1994,369,552-
554.
[29]Rondeau,B.,Fritsch,E.,Peucat,J.-J.,Nordrum,F.S.
andGroat, L., CharacterizationofEmeralds froma
historicaldeposit: Byrud(Eidsvoll),Norway. Gems
&Gemology,2008,44,108-122.
[30]Ventalon,S.,Dubois,M.,Rondeau,B.andRégnier,
S.,Mineralisingfluidpropertiesoftheemeraldde-
positofByrud,Norway.EuropeanCurrentResearch
onFluidInclusions(ECROFIXX),Granada,Spain,
2009,273-274.
[31]Grundmann, G.andMorteaniG.,Emerald mineral-
izationduringregionalmetamorphism;theHabach-
tal(Austria)andLeydsdorp(Transvaal,SouthAfrica)
deposits,EconomicGeology,1989,84,1835-1849.
[32]ThomasR,WebsterJD,DavidsonP.Be-daughtermin-
eralsinfluidandmeltInclusions:implicationsforthe
enrichmentofBeingranite-pegmatitesystems.Con-
tributionstoMineralogyandPetrology,2011, 161,
483-495.
299