American Mineralogist, Volume62, pages403410, 1977
Classificationand nomenclatureof the pyrochlore group
D. D. HoclnrHl
Departmentof Geology,Uniuersityof Ottawa
Ottawa,CanadaKl N 6N5
Abstract
The IMA Subcommitteeon Nomenclatureof the PyrochloreGroup recommendsthe following classificationand
nomenclature:
pyrochlore[Ar-.B,O6(O,OH,F)r-".pHzO]
Group
Subgroups pyrochlore,microlite,betafite
pyrochlore,kalipyrochlore,bariopyrochlore,yttropyrochlore,ceriopyrochlore,
Species
plumbopyrochlore,
uranpyrochlore(pyrochloresubgroup);microlite,stannomicrolite,
bariomicrolite,plumbomicrolite,bismutomicrolite,uranmicrolite(microlitesubgroup);yttrobetafite,plumbobetafite,betafite(betafitesubgroup).
Subgroups
are dividedaccordingto B-atoms(Nb, Ta, Ti) and species
accordingto,4-atoms(K, Sn, Ba,REE, Pb, Bi,
U). Forty-eightnamesrelatedto the pyrochloregroup shouldbe dropped,and five type specimens
shouldbe reinvestisated.
Introduction
The pyrochloregroup comprisesa seriesof cubic
oxidescontainingessential
amountsof niobium,tantalum,or titanium.Pyrochloreitselfwasdescribed
by
Wdhlerin 1826,microliteby Shepardin 1835,and
"hatchettolite" by Smith in 1877.The remaining
memberswereall describedin the presentcentury.
Prior to the late 1950's,Dana's Systemof Mineralogy(Palacheet al.,1944,p.747-757)providedthe
accepted
classification
of the pyrochloreminerals.In
pyrochlore-microlite
this classification
wasdescribed
as a series,and nine similarmineralswereappended
as "likely members"of this series.Betafiteand "djalmaite" (ibid,p.803-805)wereexcluded,but with the
cautionarystatement
that "considerable
uncertainty"
existsconcerningtheir relationshipwith pyrochlore
and microlite.Thesetwo mineralswerelatershown,
chemicallyand structurally,to retainthe pyrochlore
structurewith manyof the largercationsitesunfilled
(Borodinand Nazarenko,1957;Hogarth,l96l).
In the 1960sand 1970smany new analyses
of pyrochloremineralswere published,revealinga wide
rangeof compositions
and leadingto manynewmineral names.In the sameperiod severalschemesofl
classificationwereproposedincludingthoseof Ginz'For the IMA
chlore Grouo.
burg et al. (1960), van der Veen (1963),and Bon(1966).Adding to this growing
shtedt-Kupletskaya
complexity,the literaturecontinuedto perpetuate
rnineral"species"of questionable
validity,such as
blomstrandite,
ellsworthite,and chalcolamprite,
and
synonymssuch as mendeleeviteand betafite, neotantalite and microlite, koppite and pyrochlore.
Clearly a need existed for a universallyaccepted,
rationalclassification
and a revisednomenclature.
In viewof this need,the IMA Commissionon New
Mineralsand Mineral Names,at the requestof the
chairmanDr. Michael Fleischer,established
a Subcommitteeon PyrochloreNomenclature.A. H. van
der Veen, Arnhem, Netherlands, was appointed
chairmanin August, 1966,and he, in turn, selected
the followingmembers:
(l ) Subcommittee,
uotingmembers
S u b c o m m i t t e e on Nomenclature of the Pvro-
403
E . M . B o n s h t e d t - K u p l e t s k a y aM
, oscow,
U.S.S.R.'
T. Deans,London, England(Secretary)g
M. Gasperin,Paris,France
D. D. Hogarth,Ottawa,Canada
Akira Kato, Tokyo, Japan
L. Van Wambeke,Brussels,
Belgium
'zDiedJuly, 1974
3 Retired Feb., 1976
404
HOGARTH: THE PYROCHLORE GROUP
MicroliteSubgroupin which Nb * Ta ) 2Ti and
(2) Commission
obseruers,
non-uoting
>
M. Fleischer,Washington,D.C., U.S.A. until Ta Nb,
BetafiteSubgroupin which 2Ti > Nb t Ta.
Feb.,1968
The
abovecompositionallimits for the subgroups
C. Guillemin,Orl6ans,France
becauseof a naturalclusteringof comwere
adopted
M. H. Hey, London,EnglandsinceFeb.,1968
positionsand a relativescarcityof titanium-richanalfunctionedalmostentirelyby yses(seeFig. I Titanium-richspecies
The Subcommittee
rangefrom 33
).
In general,their criteriawerebased to 55 percentTi, whereNb * Ta + Ti : 100atom
correspondence.
members percent.Analysesreporting larger amounts of titaon publishedinformation,but in two cases,
re-examinedtype specimens.Certain decisionsre- nium may representmixtures.In contrast,most pyquireda vote,and in the few instances
whenopinions rochloresand microlitesfall in the range70-100perof memberswereequallydivided,the chairmancast cent Nb and Ta, respectively.
Subdivisionof the
the decidingvote.
of
pyrochloregroup accordingto the predominance
At the outset,memberswerefacedwith the choice Nb, Ta, and Ti atoms would thereforerestrictthe
"orthodox" names,often well-es- titaniumsubgroupto fewexamples,
of recommending
and would cause
tablishedand of deservingorigin, or appropriate wide variationsof compositionsin the pyrochlore
chemicalnames.After detailedconsideration,the subgroup.Accordingly,it was eventuallyruled that
Subcommitteeand later the Commissionruled in any mineral with 2 Ti > Nb * Ta belongsto the
favor of a chemicalnomenclature.
betafitesubgroup.
The Subcommittee
submittedits first completereare deWithin the subgroups,individualsspecies
port to Dr. Fleischerin December1971. He, in turn, finedwith respectto,4-atoms(uizNa, Ca, K, Sn,Ba,
for comments REE, Pb, Bi, U) in the followingmanner:
distributedcopiesto affiliatedsocieties
which were forwardedto the Suband suggestions,
(a) Na-Ca members.Sodiumor calcium,but no
committeein November1973.A revisedreport was otherl-atom, shallexceed20 percentof the total lthen submittedin August l9'74,and its recommenda- atomspresent,and
tions were ratifiedby the Commissionin 1975and
(b) other members.One or more l-atoms other
the reportsof than Na or Ca shallexceed20 percentof the total l1976.The presentreport summarizes
the Subcommittee(unpublished,prepared by T. atomspresent.
taken
suggestions
and decisions
Deans),incorporates
The figure 20 percentcorrespondsfavorably with
represents
the
final
con- recentpracticein describingbetafite,uranpyrochlore,
by the Commission,and
clusionsof the Subcommittee.
and uranmicrolite,the most common speciesafter
pyrochloreand microlite.
Classification
is basedon total I -ions
Theproposedclassification
The pyrochloregroup comprisesthose multiple (excludingoxonium),not on l-sites available.Thus
cubicoxideshavingthe followingcharacteristics: deficiency
of l-cations or filling of vacantl-sites by
(a) essentialamountsof niobium, tantalum,and oxonium doesnot affectthe classification.
titanium,eitherindividuallyor in combination,
Specialrulesapply in the caseof lanthanidesand
(b) the spacegroup Fd3m,
yttrium. Although no exampleis known in the py(c) the pyrochlorestructureas definedby Gaertner rochlore group of a singlerare-earthelementex(1931),and
(1930)and Brandenberger
ceeding20 percentof thel-atoms, severalrareearths
(d) the general formula Ar--B2O6(O,OH,F),-o may occur togetherin significantamounts.When
'PH,O'
their total exceeds20 percentof the total l-atoms,
In the caseof metamictminerals,compositional the Subcommitteerecommendsthat the mineral be
equivalents
which producethe pyrochlorephaseon given separatespeciesstatus.The well-knowntenof the
ignition(preferablyin vacuumor inert atmosphere) dencyfor the rare earthsto be predominantly
are admittedto the scheme.Isostructuralminerals, cerium group (light lanthanidesLa - Eu, styled
suchasantimonates
of the stibiconiteseriesandtung- ECe), or the yttrium group(Y * heavierlanthanides
statesrelatedto ferritungstite,are excluded.
Ga - Lu, styledtY), alsoprevails,andhascreateda
basedon the furthertwofold subdivision.
Threesubgroupsare recommended,
atomic proportionsof the B-atomsNb, Ta, and Ti.
Nomenclatureand species
The recommended
subgroupsare:
The current 16 speciesof the pyrochloregroup
PyrochloreSubgroupin whichNb * Ta ) 2Ti and
in this studvare listedand definedin
recommended
Nb ) Ta,
HOGARTH: THE PYROCHLORE GROUP
Table 1. Their namesreflectthe decisionto adopt
chemicalnamesin preference
to "orthodox" names.
Thus uranpyrochlorereplaceshatchettolite,uranmicrolite replacesdjalmaite,etc. Applicabilityof the
Levinson nomenclature(Levinson, 1966) was referredto, but not recommended
by theCommission.
The root namesfor species
of the Nb- and Ta-rich
subgroups,
as alsothe namesof the subgroupsthemselves,
are derivedfrom the "orthodox" namesof the
Na-Ca members.However,as no Na-Ca member
has been definitely establishedfor the Ti-rich subgroup, the Subcommittee
recommends
that betafite,
the mostcommonmember,be usedasroot namefor
this subgroup.
The bismuthomicrolite
of Zalashkovaand Kukharchik(1957)was considered
as a new speciesbut
rejectedby the Subcommittee
becauseit contained
insufficientBi(4 atom Voof the ,{-ions). The Subcommitteerecommendsthis name be used for the
bismuthmemberof the microlitesubgroupasdefined
in the precedingsectionand first described(as westgrenite)by Knorring and Mrose(1963).
The use of additional adjectivalprefixesis optional, and should normally be restrictedto the
A-atom next in abundanceafter thb principalconstituent,followingPalacheet al. (1944,p. 43).Thus
bariopyrochlore
from the type localitycan be called
(Ba 44Vo;Sr 32Voof theAstrontianbariopyrochlore
atomspresent).
Recommended
namesare givenbelow.Note that,
405
Ta
Nb
Fig l. The threesubgroups
of the pyrochloregroup.Compositions are plottedatomicallyfrom data in Bonshtedt-Kupletskaya
( 1966).Mineralsno longerincludedin thegroup(mineralswith the
samiresitephase,"hatchettolite"from Hybla, Ontario, and "titanpyrochlore"from Tangen,Norway) are not plotted.
with the approvalof the Commission,
six newnames
are introduced: kalipyrochlore, bariopyrochlore,
yttropyrochlore,ceriopyrochlore,stannomicrolite,
is redefined.
and bariomicrolite.Bismutomicrolite
Speciesof the pyrochloregroup
Pyrochlore(Wcihler,I 826)
Table l. The pyrochloregroup
S U B G R O U P Sd e f l n e d
Nb,
viz
Na+Ca, but
>202 total
by B atoms
Ta. Tt
no other
A -atons
PYROCHLORE
Nb+Ta>2Tl
Nb>TT
MICROLITE
NH Ta>2Ti
Ta>Nb
B E TA F I T E
2 Tt >Nb+ Ia
A-atons
pyrochlor
nicrolite
SPECIES deflned
by A -atohs
kallpyrochl
vaz
K,Sn,Ba,REE,
Pb,Bi,u
one or more A-atons,
than Na or Ca, >202
A-atoms
Species naoed by
abundant A -aton,
than Na or Ca
other
rotal
nost
other
stannonicrollte
Ba
bariopyrochlore
R E E*
yttropyrochlore
ceilopyrochlore
Pb
p lunb opyr och 1o re
Bi
U
ba! ionic!oIite
yttrobetaf
(tY>tCe)*x
(XCe>tY)
Plunbonlcrolite
Plumbobetafi
b isnu Eomlcro lit
uranpyrochlo
y a 1La + lu), and
6dL puLpoaaa 06 apecio4 detltuitioft,
.|.REE=
" lY - Y + lcd - Lul; LCe = La + Eu.
re
ur anmic r o 1l t
REEcoun-tt M oftL A-etom.
1te (tY>tCe)
betafite
HOCARTH: THE PYROCHLORE CROUP
Kalipyrochlore (described but not named by Van
W a m b e k e , 1 9 6 5 ,p . 9 - 1 5 )
Ba r i op y r o chl or e (name replaces pandaite, q.u.)
Yttropyrochlore (Kupriyanova, unpublished; described as obruchevite by Kupriyanova et al., 1964,
anal.63)
Ceriopyrochlore (name replaces marignacite, 4.u.)
Plumbopyrochlore (Skorobogatova et al., 1966)
Uranpyrochlore(Holmquist, 1896; name replaces
hatchettolite,q.u.)
Speciesof the microlite subgroup
Microlite (Shepard, 1835)
Stannomicrolite(name replacessukulaite, 4.u.)
Bariomicrolite (name replaces rijkeboerite, q.u.)
Plumbomicrolite(Hey, 1964,p. 1147;based on Saf i a n n i k o f fa n d V a n W a m b e k e , l 9 6 l )
Bismutomicrolite (name replaces westgrenite, 4.u.)
Uranmicrolite (Strunz, 1957; name replacesdjalmaite, q.u.)
Speciesof the betafite subgroup
Yttobetafte (Kalita, I 959)
Plumbobetafite (Ganzeev et al., 1969)
Betafite (Lacroix, 19l2b)
Synonyms, doubtful and discredited names, and species
not belonging to the pyrochlore group
The many synonyms and other names associated
with the pyrochlore group are listed alphabetically
below, and discussedin light of the proposed nomenclature.
Aluminobetafite (Kawai, 1960) may possibly belong to the pyrochlore group and betafite subgroup,
with unusual gross substitution of Al and some Sn
and U. More data are needed.
Azorpyruhite (Hubbard, 1886)probably belongsto
the pyrochlore group, but as quantitative analysesare
lacking, the mineral cannot be classifiedor renamed
at this time.
Blomstrandile(Lindstrdm, 1874) has beenassumed
to belong to the pyrochlore group. It is possibly
uranpyrochlore, but adequate analyses are lacking,
and new data are desirable.
Calciosamarskire(Ellsworth, 1928)has the composition of uranian yttropyrochlore, but the mineral is
metamict, and proof that it belongsto the pyrochlore
group is lacking. Van Wambeke (1970) suggeststhat
a somewhat similar metamict mineral from Zaire
may be yttrian uranpyrochlore with a high proportion
of Fe3+in the B-positions.Further study seemsdesirable before deciding the status of this mineral.
(Lin et al., 1973)is a cerian
Ceruranopyrochlore
pyrochlore.
The nameshouldbe dropped.
Chalcolamprile(Flink, 1898; 1901) contains a
inclusions"(Flink,
"large number of microscopical
an impure
1901,p. 163)and apparentlyrepresents
pyrochlore.The 10.86percentSiO, may be due to
impurities.The nameshouldbe dropped.
(Yllliers, l94l) is an unnecessary
Columbomicrolite
synonym of pyrochlore. The name should be
dropped.
Djalmaite (Guimardes,1939) is a synonymfor
uranmicrolite.
The nameshouldbe dropped.
Ellsworthite(Walker and Parsons,1923a)conThe
forms to the new definition of uranpyrochlore.
nameshouldbe dropped.
Endeiolite(Flink, l90l) is probablyan impurepyrochlore. The few tiny analysed crystals "were
The I L48 percentweightloss
scraped"from aegirine.
in HF and HrSOnwas assumedto be SiOr,essential
to the compositionof the mineral.The nameshould
be dropped.
(Hermann,1850)is an earlysynonymof
Fluochlore
pyrochlore, not used by later writers. The name
shouldbe dropped.
Haddamite(Shepard,1870) is assumedto be a
are lacking.The
synonymof microlite,but analyses
nameshouldbe dropped.
Hatchettolite(Smith, 1877) is a synonym of
nameshouldbe dropped.
uranpyrochlore.The
(Hermann,1850)is an earlysynonym
Hydrochlore
of pyrochlore,not used by later writers. The name
shouldbe dropped.
Hydropyrochlore(lvanov et al., 1944)is probably
an alteredmetamictpyrochlore.The nameshould be
dropped.
Koppite(Knop, 1875)is a poorly definedvarietyof
pyrochlore.The type specimenis not available,but
most specimensfrom the type locality arcpyrochlore
(seeVan Wambeke,1964,p.67 for analyses).
Jakob's
1931)shows9.73 percent
analysis(Brandenberger,
The name
Fe2O3,and contaminationis suspected.
shouldbe dropped.
Marignacite(Weidmannand Lenher, 1907)is a
synonym of ceriopyrochlore.The name should be
dropped.
(Vernadskii,1914;
Mendelyeeuite
or mendelejeuite
analysis
1923)is a synonymof betafite,the accepted
(seeChukhrovand Bonshtedt-Kupletskaya,
1967,p.
175-l'76,anal. 9) conformingto the redefinitionof
this species,
althoughthe proportion of uraniumis
minimum.The nameshould
little abovethe necessary
be dropped.
HOGARTH: THE PYROCHLORE GROUP
Metasimpsonile
(Simpson,1938,p. 88; Bowley,
1939;Taylor, 1939,p. 93) is a synonymof miuolite.
The nameshouldbe dropped.
Mumbite(Van Wambeke,1970)is a synonymof
plumbomicrolite.The name should be dropped.
Neotantalite
(Termier,1902)has long beenrecognized as eithermicroliteor a closely-related
mineral.
The originalanalysis(by Pisani)showedFe and Mn
as the principal l-atoms and the absenceof Ca.
Reexamination
of Termier'stype materialby Gaspein (1972\showedthe mineralto be metamictmicrolile with largedeficiencies
in the l-ions, which may
be filled by Ba, Pb, U, and Ca. Fe and Mn were
presentas impurities.The nameshouldbe dropped.
Niobpyrochlore
(Machatschki,1932)is an unnecessary synonym for pyrochlore.The name should be
dropped.
Niobtantalpyrochlore
(Machatschki,1932),implying a compositionwith Nb ", Ta, must be renamed
eitherpyrochloreor microlite,accordingto the analysis.The nameshouldbe dropped.
Nuolaite(Lokka, 1928),a mixture of yttropyrochlore and other niobium oxide mineralsrelatesto
wiikite (q.u.),must be discreditedas a species.
(Kalita, 1957)is a namelatershownto
Obrucheuite
have been given to two differentspecies(Gorzhevskaya and Sidorenko,1969).One of these,brown
obruchevite,after heatingto 700oC,crystallizedto
the samiresile^l phase(4.u.).The other, black obruchevite,wassubsequently
renamedyttropyrochlore
(Kupriyanova, 1970, unpublished). The Soviet
Union's Commissionof New Minerals(KNM) and
MineralogicalTerminologyhave recommended
the
nameyttropyrochlorereplacethis type of obrucheuite.
Pandaite(Jiiger et al., 1959) is a synonymfor
bariopyrochlore.
The name should be dropped.
Priazouite(Yurk, l94l1, 1956,p. 24), previously
regardedasan alteredpyrochlore(Dzhun,1963),has
beenshownto belongto the samarskilegroup (Gorzhevskayaand Sidorenko,1974)and must be excludedfrom the pyrochloregroup.
Pyrochlore-microlite
(Beuset al., 1962),implying a
compositionwith Nb ^, Ta must be renamedeither
pyrochloreor microlite,accordingto the analysis.
Pyrochlore-wiikile(Strunz,1957),beinga mixture,
must be discredited;seewiikite, below.
Pyrrhite (Rose, 1839,p. 5621'1842,p. 383-385)
belongsto thepyrochloregroup,but cannotbe classified becausethe type materialhas not beenanalyzed.
The nameshouldbe dropped.
(van der Veen,1963)is a synonymfor
Rijkeboerite
bqriomicrolite.The name should be dropped.
Samiresite (Lacroix, l9l2a) has the composition of
a plumbian uranpyrochlore (seeVan Wambeke, 1970,
p. 138). However, although this mineral is metamict,
apparently with octahedral habit, it recrystallizeson
heating (Gorzhevskaya et al., 1966; Gorzhevskaya
a n d S i d o r e n k o , l 9 7 l ) t o a p h a s e ," S " , r e l a t e d t o
synthetic UTarOro (Gasperin, 1965) and lesser
amounts of a pyrochlore phase.The name should be
dropped.
Scheteligite(Bjlrlykke, 1937)may possibly belong
to the betafite subgroup, with complex substitution
by Y, Mn, Sb, W, Bi, but more data are needed.
Silicate-wiikite (Strunz, 1957)must be discredited,
being a mixture; seewiikite.
Stibiomicrolite(Quenseland Berggren, 1938)must
be discredited, being a mixture of microlite, stibiotantalile, and stibnite(seeRos6n and Westgren,1938)
Sukulaite (Vorma and Siivola, 1967) is a synonym
for stannomicrolite.The name should be dropped.
Tangenite(Gagarin and Cuomo, 1949)was a name
presumptuously given to titanium-rich "betaftes"
from Norway (Tangen quarry near Kragerl). Two of
the analysescorrespond ro betafte, and one to the
titanian equivalent of pyrochlore. Recently W. L.
Griffin, of the Mineralogisk Museum, Oslo, has
shown that the specimens analyzed were mixtures
(seetitanopyrochlore).The name is discredited.
Tantalbetafite(Kalita and Bykova, l96l) is a synonym for betafite.The name should be dropped.
Tantalohatchettolite(Villiers, l94l) is a synonym
for uranmicrolite. The name should be dropped.
Tantalo-obrucheuite (van der Veen, 1963), intended for the yttrium-rich member of the microlite
group, has not been found.
Tantalpyrochlore (Machatschki, 1932) is a synonym of microlite. The name should be dropped.
Titanbetafite (Ginzburg et al., 1960) is a synonym
of betafite as redefined above. The name should be
dropped.
Titanmicrolite (Strunz, 1966, erroneously ascribed
to van der Veen, 1963),with Ti ) Ta > Nb, has not
been found.
Titano-obrucheuite(van der Veen, 1963) is a synonym of yttrobetafite, and the name must be discarded.
Titanopyrochlore (Machatschki, 1932) was named
as a hypothetical titanian equivalent of pyrochlore.
O n e o f t h e a n a l y s e so f B j l r l y k k e ( 1 9 3 1 , a n a l . 3 ) , f r o m
the Tangen Quarry near Kragerf , Norway, conforms
to a dominantly calcian member of the betafite subgroup. W. L. Griffin (correspondence,April 1974)
made a microprobe analysisof Bjlrlykke's specimen
HOGARTH: THE PYROCHLORE GROUP
and found it to be composedof at leastfive different
References
phases. A "hatchettolite" from Hybla, Ontario
ZusamAnt-Wuorinen,J. (1936)Der Wiikiteund seinechemische
(Walker and Parsons,1923b,anal. l) approaches mensetzung.Bull. Comm.gbol. Finlande,ll5, 213-229.
titanpyrochlorein bulk, but the material is in- Beus,A. A., and A. P. Kalita(1961)Recentdataon the so-called
wiikite, Dokl. Akad. Nauk SSSR, /41, 705-708.(In Russian).
homogeneous(Hogarth, unpublisheddata). The
-,
E. A. Severov,A. A. Sitnin and K.'D. Subbotin(1962)
nameshouldbe dropped.
Albitized and greisenizedgranites(apogranites).Izoest.Adad.
Westgrenite
(Knorring and Mrose, 1963)is a synlVazftS,SSR,Moscow. 194p. (In Russian).
onym of bismutomicrolite.The name should be Bjdrlykke,H (1931)Ein Betafitmineralvon Tangenbei Kragerii.
dropped.
Norsk Geol.Tidsskr.,12,'13-88.
( 1937)Mineral paragenesis
n€ar
of somegranitepegmatites
IViikite(Ramsay,1899,p. 379)anda- andB-wiik- Norsk
Kragerl,
southern
Norway.
Geol. Tidsskr.,17, l-16.
ile (Ant-Wuorinen, 1936) are mixtures of yttropyof the pyE. M. (1966)Systematization
rochloreor other membersof the pyrochloregroup Bonshtedt-Kupletskaya,
rochlore-microlitemineral group. Zap. Vses.Mineral. Obshwith euxeniteand silicates(Fauquier,1960;Beusand
chestua95, 134-144.(In Russian).
Kalita, l96l) and must be discredited(seealsopyro- Borodin, L. S., A. V. Bykova,T. A. Kapitonovaand Yu. A.
andits niobianvariety.
Pyatenko(1960)New dataon zirconolite
chlore-wiikiteand silicate-wiikite).
(In Russian).
Nant
134,
ll88-l
19l.
Dokl.
Akad
SSSR.,
Yttrohatchettolite(Kalita, 1959) has insufficient
and I. L Nazarenko(1957)Chemicalcompositionof pyuranium to be classifiedas uranpyrochlore.
It is synrochloreand isomorphicreplacements
in the ArBzXr molecule.
onymous with yttropyrochlore.The name should be
(In Russianwith English
No.4 [for 1957],2'18-295.
Geokhimiya,
dropped.
summary).
and T. L. Richter(1956)The newmineralzirconoZirconolite and niobozirconolitefrom U.S.S.R.
oxide of the ABrOt type. Dakl. Akad. Nauk
lite-a
complex
(Borodin et al., 1956;1960)are synonymouswith
SSSR,1/0, 845-848.(ln Russian).
zirkelite(Hussakand Prior, 1895),Parkerand Flei- Bowley,H. (1939)Simpsonite
(sp.nov.)from TabbaTabba,Westscher(1968,p. 3l) have listedniobozirconolite
as a
ern Australia.J. R. Soc. W. Aust. 25.89-92.
member of the "pyrochlore-betafite-microliteBrandenberger,
E. (1931)Die Kristallstrukturvon Koppit. Z.
Kristallogr , 76, 322-334.
series,"but its monoclinicsymmetryexcludes
it from
Eds.(1967)MinChukrov, F. and E. M. Bonshtedt-Kupletskaya,
the pyrochloregroup (Pudovkinaet al., 1974).
eraly, Yol 2, Pt. 3, Nauka Press,Moscow.(In Russian).
V, S. (1963)New data on the characteristics
Dzhun,
ofpriazovite.
Conclusions
(In Ukranianwith
DopouidiAkad. Nauk URSR,10, 1379.1384.
The proposedschemeof classificationpermitsthe
in Russianand English).
summaries
from the
addition of new speciesto the group when data be- Ellsworth,H. V. (1928)A mineralrelatedto samarskite
Woodcox Mine. Hybla, and from Parry Sound,Ontario.Am.
comeavailable.
In namingtheseminerals,we recomMineral.. 13,63-68.
mend a chemicalnomenclature,
as outlinedabove. Fauquier,D. (1960)Sur la "wiikite" et la "loranskite."C. R. Acad.
The following mineralsor variantsare poorly deSci, 250. 3032-303.4.
fined: aluminobetafite,
azorpyrrhite,blomstrandite, Flink, G. (1898)Ber?ittelse
om en mineralogiskresai Syd-Gr6nland sommaren1897.Medd. Gry'nland,14,221-262.
calciosamarskite,
Type materialsshould
scheteligite.
_
(lg0r) on the mineralsfrom Narsarsukon the Firth of
be reinvestigated,
and their mineralogical
statusconTunugdliarfik in southern Greenland. Medd. Grfnland, 24,
firmed.
7- I 80.
von Loparit
Gaertner,H. R. von (1930)Die Kristallstrukturen
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Acknowledgments
l-30.
gratefullyacknowledges
The Subcommittee
the help of Dr. Mi- Gagarin,G. and J. R. Cuomo(1949)Algunasproposiciones
sobre
past-Chairman
chaelFleischer,
of the IMA Commission
of New
nomencfaturamineralogica.Comun.insl. nac,inuest,cienc,nat,
Mineralsand MineralNames,and ProfessorGlaucoGottardi,the
del Museo Argentino Cienc. Natl. "Bernardino Riuadauia,"
presentsecretaryof the Commission.Much assistance
was given
Cienc.geol.,/, No. 5, 2l p.
by the All-Union MineralogicalSocietyof the USSR,especially
by Ganzeev,A. A., A. F. Efimov,and G. V. Lyubomilova(1969)
ProfessorsV. A. Frank-Kamenetskii,Chairman of the Soviet
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