331
Canad.ianM ineralo gi*tVol. 31,pp.331-336(193)FROM
MOZARTITE,
GaMn(OHlSiO{A NEWMINERALSPECIES
THEGERCHIARA
MINE,NORTHERNAPENNINES,ITALYRICCARDO BASSO, GABRIELLA

LUCCHETTI.qND LIVIO AFIRO

Dipartinmw di ScienaedellnTenadell'Universitd, CorsoEuropa26, I-16132 GenovqItaI!
ANDREAPALENZONA
Istituto di Chimica Fisicadell'Universitd, CorsoEuropa26, I-16132, Gewvu lta$

ABSTRACT
Mozartiteoccursat theCerchiaramine,Val di Vara,northernApennines,Italy. Associatedmineralsarepectolite,calcite,quanz
asminute
andhausmannite.
Mozartiteandtheassociatedminerals
fillwideveins in ophioliticmetacherts.Mozartiteusuallya14rcars
anhedralcrystals,but somesubhedralprismatic[@] crystalshavebeenfound.It is transparent,deepte{ stronglypleochroicand
biaxial positive,with 2Vo6.= JQ(2)",a 1.840(5),F 1.855(5),y 1.920(5).The meanchemicalcompositionleadsto the empiricalformula Can.e6(MnL00Ab.0r(OH)t.s0S5.eOa.6.
It crystallizesin^spacegroupF2ppy with a 5.838(l), b 7.?24(l), c 8.690(l) A
and5.558(011).
linesin the X-ray powderpattemld n A(hkl)l are2.584(2Ll),2.687(013),3.070(120)ard Z = A.T\e strongest
Mozartite is isostructral with the silicate wagnatite, the vanadatetangeite (calciovolborthite)and the arsenatesaustinite,
conichalciteand nickelaustinite.The crystal strucnre was refined to R = 0.V27,The namehonon Wolfgang AmadeusMozart(l75Gl79l); the mineralwasfound in the yearmarkingthe 2@th anniversaryof his death.
Keyvord::mozannte,occurrence,physicalproperties,chemicalcomposition,powderpattem,structurerefinemen!Cerchiaramine,
Italy.
Sol"rMerns
Nous avonsd6couvertIa mozartite,nouvelleespbcemindralq d la mine Cerchiaradansla partienord desAppnins, en ltalie.
Lui sont associ6spectolite,calcite,quartzet hausmannite,en veinesqui recoupentdesm6tachertsophiolitiques.La mozartitese
pr6sentenormalementsousforme de fids petits cristauxxdnomorphes,quoiquenousavonstrouv6 descristauxsub.idiomorphes
rougefonc6,fortementpl6ochroique
etbiaxepositive,2Vo6r50(2)', o 1.840(5),I 1.855(5),y 1.920(5).
[1@]. Elle esttransparente,
Ellerdpondllasym6trie
LesdonneeschimiquesmoyennesmdnentdlaformuleempiriqueCa6.es(Mn1.mAl0.or(OH)1.00Sis.9Oa.6.
du groupe spalal F212py a 5.838(l), b 7.22A(l), c 8.690(l) A, Z = A. Les quatreraiesles plus intensesdu clich6 de ditfraction
la mozartitepossddela m6mestucture que le silicate
Id w A(l*J11sont 2.584(211),2.687(013),3.070(120),5.558(0ll).
wagnatite, le vanadatet"ngdite (calciovolborthite),et les arsenatesaustinite,conichalciteet nickelaustinite.Nous avonsaffin€ lastrucflre cristallinejusqu'i un rdsiduR de 0.027.La mozartiteayant6t6d&ouvert€ en 1991,le nom choisisoulignel'anniversaire<lela mort de WolfgangAmadeusMozart (175G1,791).
(Iraduit par la R6daction)
Mots-cl6s:mozartite,nouvellees$ce min6rale,propri6t6sphysiques,compositionchimique,ctch6 de diffuaction& affinement
de la structure,mine Cerchiaraltalie.

The new mineral is a basic calcium manganesenesosilicatecloselyrelatedto mineralsofthe adeliteand
Continuingstudiesof occurrencesof manganiferous descloizitegroups. It representsthe Mn analogueof
mineralizationin ophiolitic sequencesof the northern wagnatite CaAl(OH)SiO4(Sarpet al. 1976,McNearet
Apennineshaveledto tle identificationof anew silicate al. L976,Pabstu al. 1977).T\e namehasbeenchosenmineral specie$,mozartite,in the Cerchiaramanganese in honor of Wolfgang Amadeusivlozart (1756-L791),
mine, localed itr Val di Vara in eastemLiguria, Itaty. sincethe mineralwasidentified asa new sp€ciesduring
Assemblagesof silicate and carbonateminerals from the 1991, year marking the 200th anniversaryof his
lhis minehavebeen
describedbyLucchetderal. (1988), death. This unconventionalchoice is justified by theclose associationof geological and mineralogicalsciBassoe/ aL (1989ab) andCabellael aI. (1990).
INrRoDUciloN332

THE CANADIAN MINERALOGIST

enceswith Mozart's music,andespeciallywith his lastopera'"The
MagicFlute'(Whitaker 1991).Theminerat
and the name have been approved by the I.M.A.
Commission on New Mnerals and Mneral Na:nes.
Type material is depositedin the collection of the
Dipartimentodi Scienzedella Tena, Sezionedi Mineralogia Universiti di Genova.

DATA FORMOZABTITETABLE 2. ETECTBON-UICBOPBOBE

Bdge

ueu

(rtZ)

0.00 - 0.15
26,'.19- 2f .20
0.40 - 0.70
38.46 - 39.01
28.75 - 29,66

fgo
Cao
Al203
Iiln20s
gioz
Total

(rtg)

0.05
27.O8
0.49
34.12
29,25
95.59

OccunneNcsANDPHYSICALPRoPERTIBS
Mozartiteforms reddishbrown aggregatesof minule difference, after a microprobe check indicated theanhedralcrystalsintergrown with pectolite and minor absenceofdetectableF. The calculatedamountofH2O
amountsof calcite, quartz and hausmannite.Mozartite agrees with the value inferred from the sfructuralmineralsfill largeveinsthatcross-cut analysis.Spot analysesshow neittrer sipificant variandthe associatedmassive braunite interbedded within the ophiolitic ations of composition nor compositional zoning inmetachertsat the Cerchiaramine, nearFaggionaVal di individual crystals.The meanchemicalcompositionis
Vara Ia Spezia easternLiguria ltaly. The size of the reportedin Table2, alongwith anindicationof variabilindividual grainsof mozartiteranges
fromO.l to 0.5mm, ity. The empiricalformul4 basedon five oxygenatoms,
and somesubhedralsingle crystals,included in calcite is: Can.es(Mn1.mAlo.ot(OH)1.esSie.eOa.6.
or pectolite,developwith stocky prismatichabit elongateparallelto [100]; the dominantprism is terminated
X-RAY PowDm.-DrFRAcrroNDArA
by a bisphenoid.Neither twinning nor cleavagewas
observed,and the fractureis conchoidal.The hardness
The X-ray powder-diffraction analysis was percould not be delerminedowing to fts small grain-size;
formed by a Guinier STOE camerausing CuKcrradiabemicro-indentationmeasurements
wereunsuccessfrrl
andsilicon asaninternaltion (graphitemonochromator)
causeof the brittlenessof the mineral. The measured
standard.Relative intensities were assignedvisually,
density,using Clerici solution and a Westphalbalance,
and the reflections were indexed on the basis of theis 3.63(4) g/cm3;the calculateddensity is 3.68 g/cm3. patfem
calculatedby the Lazy Pulverix program(Yvon
The indices of refraction were determinedby Cargilleet aL L977) using the results of the single-crystal
oil-immersion liquids at 25'C for 589 nm; the opticalstucture analysis.The cell parametersrefined fromaxialanglewasobtainedwith afive-axisuniversalstage. powderdataarea 5.837(l), b 7.229(l), c 8.690(2)A.
The optical propertiesaresummarizedin Table 1.
Measuredand calculatedpowderdiffraction data arereportedin Table 3.
Cunmcar, CoMPosmoN
oFTFIECRYSTAL
Srnucrunr
REril.rENGNr
Sixteenspot chemicalanalyseswere carried out bymeans of a PHILIPS SEM 515 scanning elecfon
An anhedralcrystal,measuringapproximately128x
microscopeequipped with an EDAX PV9100 spec102x26 pm, was mountedon an ENRAF-NONIUS
trometerin energy-dispersion
mode,with an accelerating voltageof 15kV anda beamcunent ofabout 2 nA.
Diopside(Mg, Ca),rhodonite(Mn) andanorthoclase
TABTB 3. X-BAY POTDEB.DIFFBACTION DATA FOB ITOUAETITE(Al, Sl) were used as referencestandardsfor the only
lle@u!9d
calculated
elementshavingatomicnumbergreaterthan 10that are
til€suledcolculated
r
I
d
d
I
hkl
l
d
d
presentTheH2Ocontentcouldnotbe detenninedowing h k l
to the paucity of material, but was calculared by
2.081 W
2.081 10
S
0
I
1
0
0

TABLE 1. OPIICAI

Trdspareot
Lustrelritreous
colour:deep redS!.€ak!
rgd
llon- f luofsscstri
gtrodgPlochrcieo:
X: yello{-bromy:yelLorZ : orage-red

PBOPERTIESOF UOZABTITE

poBitive
Bidi.alElongationr
tpEitiveo.ientatlotr;
Z : &
a :

1.840(5)p = r.855(5)/:1.920(5)

1
2
I

0
I
4

2 v o b s= 5 0 ( 2 ) "2vcar".52.8"
d values

5.555 86
4.024 23
3.612 37
3,012 13
2,115 202.689 73
2.584 100
2.508 38
2.442 35
2.423 tO
2,32t 92,291 n2,270 26
2,260 t9
2,151 2S
2,113 I
2,L06 4
de

in A.

5.558
4..025 l{
3.613 ri
3.0?0 S2.116 w
2.681 S2.584 V8
2.509 H2,447 rt2,422 W
2.320 W
2.296 W
2.269 r2.260 r2.79',1 I
2,1?3 W
2.106 VW

1
1
0
2
0

0
2

0

2.012 26
1.981 3
1,960 5
1,862 11
1.837 6
1,477 20
1.806 3
7,716 2x.765 18
l.?43 19
1.713 91.668 30
1.5?6 g1.5?0 131.564 51
1.536 18

2.013 r1 . 9 8 0V ! L
1.959 t{/a1.862 T
1.836 Vr{
1.817 t{1.806 Vr{
1 , 7 1 5V W
1.766 r1.143 ri
1.?13 11{1.669 r{1.577 l\f1.570 Vfl
1.565 lil
1.538 !r333

MOZARTITE FROM THE NORTHERNAPENNINESDATA FORI{OZABTITE
TABtf, 4. CBYSTALSTBUCTURE
Cadn(OH)st04

Idealized fornula
Fomula froB
relineBent
sinctureca(Uuo.saAlo. os ) (otl) 3i0a

Sprce grcup
a (A)'b (A)c (A)v (43)p (MoKa, !o-r)

P2t2t2t
5 . 8 3 8 (1 )'t .224(rl8.6e0(1)
366.5
4.86

Itlesured reflecti.ons(Includlug Friedel paire)
IndelBtrdeni ref leciions
Obaerved reflectlong (l > 3dr)
Extinction colrection

1930
1056
660
4 . 9 (5) x 1 0 - a

Rr (observed)
R (observed)
R (all)'LabeliDg

of

0.024
0.027
0.068

ses

rccordingtoParth6& Gelato(1984)TABLE 5. ATO!'IC COORDINATESAIID EQUIVATEN1 ISOTROPIC TTilPEBATUBEFACToBS (HATIITON 1959) FOB MOZARTITE

Ato!'

glie

Ca
!h,/Ar
si
01
02
o3
04
05

1,
0.94(5)/0,06
1.
1.
1.
l.
1.
1.

gg (42 )a/cvlb

occupscy0 . 0 2 1 6 ( 2 )0 . 3 7 4 8 ( 2 ) 0 . 6 7 4 1 ( 1 ) 0 . 7 2
0.1468(2\ 0,2570(2) 0.9964(1) 0.43
0 . 5 1 0 3 ( 3 )0 . 6 3 0 7 ( 2 ) 0 . 8 1 6 4 ( 1 ) 0 . 5 4
0 . 4 9 1 3 ( 7 )0 . 4 5 3 4 ( 4 ) 0 . 9 3 3 6 ( 3 ) 0 . 6 0
0 . 5 7 1 6 ( 6 )0 , 7 9 9 5 ( 4 ) 0 . 9 3 9 7 ( 4 )0 . 8 5
0 . 2 7 2 9 ( 7 )0 , 6 5 8 6 ( 5 ) 0 . 7 2 1 8 ( 4 , 0 . 6 2
0 . 7 3 8 87( ) 0 . 6 2 3 4( 5 ) 0 . 7 0 6 8 ( 4 ) 0 . 7 0
0 . 0 0 3 3 ( ? )0 , 3 9 4 3 ( 4 ) 0 . 9 4 1 4 ( 3 ) 0 . 5 6'Nu@berlngof atous rccording lro McNoeret al.

(1976)DISTANCIs(A) TORTIIE COOBDINATIONTABTE6. IIrTERATOIIICPOLYHf,DRA
IN MOZABTITEsi - 01
- 02
- 03
- 04
Average

1.640(3)1.662(3)r,624(4)1.640(4)1,642

ittr - 01- 01',
- 03
- 04
- 05
_ 05'
Average

2.130(3)2.17r(3)2.029(4)2,024(4J
1.8?3(3)1.858(3)2,014ca - 01
- 02
- 02'
- 03
- 03'
- 04
- 04,
- 05
Average

TABLT ?. EDCELEXONfi' (T) AI{D ANCLSS(')
MLY!{8DBA !N }IOZAIIIITB
01 -8i-02-03-o4
02 -si-o3-o4
03 -st-o4
Averego2.645(4)2.685(5)2.?35(5)2.768(5)2.582(5)2.73614')2,616

100.80(15)110.68(21)113.01(21)114.?7(18)102.89(17)113.83(15)109.3301 -!t!-03

2.8?3(5)2.903(5)2.',r4'7(4)3.020(6)3.051(6)2.996(5)2.881(5)2.73?(4)2,19214)
2.?4r(5)2.?85(5)2.?08(5)2.A52

87.36(13)S8,63(14)86.03(14)98.21(13)93.10(15)91.06(14)90.56(14)85.20(14)91.2?(14)89.58(14)91.14(14)88.35(14)
90.04

-05
-05'
01'-l'tn{3
-o,r
-06
-o5,
03 -rn-05-05'
04 -ritu-os,o5'Ar€.alle

2,432(312,629(3)2.456(3)2.493(4)2.555(4)2.515(4)2.456(4)2.329(3)2.483

FOE TTII COOBDINATION

01 -ca-02
-02'
-03'
-04'
02 -ca-o3'-0402'-ca-o2
-03
-04
-04'
-ca-o403-o4'-05
03'-ca-04-04'-06
04 -ca-o504'-ca-05
Average

3.225(5)2.515(4)3.051(5)2.903(5)3.086(5)2.582(5)3.r83(2)3.182(5)3.67?(5)3.993(5)3.131(4)3.416(6)2.741(5)3.916(6)3.131(4)3.124(5)2.?85(5)3.046(6)3.161

79.07(11)62.?5(10)?5.40(12)12.87{t2l?3.05(12)60.20(11)71.4117)80.01(11)95.41(12)108.?8(13)?7.39(10)8?.28(13)69.17(12)r01.13(12)?7.33(9)79.40(13)?0.05(13)79.0t(13)19.21

CAD-4 automatic single-crystal diffractometer. The
cell parameterswere determinedand refined, using 25
reflections within the angular range l8o < e < 21".
Diffraction intensitiesweremeasuredupto0 = 30ousing
gaphite-monochromatedMoKa radiation and operating in the o - 2e scanmode.An absorptionconection
wasappliedusingthery scanmethod(North el aL 1968).
The [,auesymmetryof thereciprocallatfrceis mmm,and
systematicextinctionsare presentfor ft00: h = 2n + lo
l = 2n + l.TlT spacegroupis
0ft0:& = 2n + l, and0OI:.
thereforcP2t2t21.
The structure,solvedusing the Pattersonmap, conby chemifirmed the isotypy with vuagnatltesuggested
cal formula unit cell and spacegroup. The structuralmodelwasrefinedthrougheight cyclesofleast-squares
refinement,carried out by a modified version of the
ORFLS progam (Busing et al. 1962).The scatteringfactors for neutral atoms, including corrections foranomalousdispersion,weretakenfromthe Intemational
Tablesfor X-ray Crystallography,vol. ry (1974).Total
occupancywas fixed for Ca and Si in their respective
sites.Scalefactor, coefficient of secondaryextinction,
occupancy of Mn versus Al in the octahedralsite,
coordinatesand temperaturefactors were simultaneously derived. Anisotropic temperature-factorswere
introducedafter the fourth cycle. Experimentaldetails
andrefinementresultsaresummarizedin Tables4, 5, 6
and7,
A secondrefinement,underthesameconditions,wasusing the antipodalcoordinates| - x, | - y,
I - z and led to the final valuesR(obs) = 0.032 andR (obs) = 0.026.The Hamiltontest (Hamilton 1965)
favors the lrst configuration at the 0.05 level ofstatisticalsignificance.
Finally, geometricalconsiderationsandformula balancesuggestthe presenceof a hydrogenbond, in viewof theshortdistanceO5-O2 [2.474(4)A].T behydrogenatom, located on a difference Fourier map at 0.014,
0.529,0.983,is involvedin a stronghydrogenbond,by the distancesO5-H
is characterized
whoseg^eometry= 1.04A, H.-OZ= 1.45A andtheangleo5-H...o2 =t67.2".
Tablesof F", o(F") and anisotropicthermalparameters are availablefrom the Depositoryof UnpublishedData" CISTI, National ResearchCouncil of Canada
Ottawa-OntarioKIA 0S2.
DIscussIoN
Among the compoundswith the general formula
five mineralswhosestructureshavebeen
CaM(OH)TOA,
describedin the spacegroupYLpt2t are isostructural
with mozartite.In additionto wagaatite CaAl(OH)SiO4(McNearet a/ 1976),four membersof theadelitegroupwith pentavalentAs and V in the T site and divalentcationsZn, Cu andNi in theM siteareinvolved:austinite(Giuseppetti& Tadini 1988),conichalCaZn(OH)AsOa

334

TIIE CANADIAN MINERAI.OGIST(b)

Ftc. 1. Drawing of the arrangementofoctahedraandtetrahedra in the struchres of (a)mozartiteCaltIn(OIDSiOaand
Ba2@'e$,n{fi)@)gamagarite(OlDffOdz. Empty circles
representhydrogenatoms,andfilled circles representCa atoms in mozartite and Ba atomsin gamagarite.

MOZARTITE FROM'ITIB NORTHERNAPENN]NES

33s

199O)
cite CaCu(OH)AsOa(Qurashi & Bames 1963), describedasrecombinations(Lima-de-Fariaeral.
nickelaustinite Ca(Ni,ZnXOH)AsO, (Cesbron et al. of the structuraltype representedby the third category.
1987) and tangeite(calciovolborthite)CaCu(OH)VOo The first two categoriescontainlayerscut out from the(Bassoera/.1989c).
archetypalstructure(third category)by omitting, inl),theoctahedrallycoordinated
A comparisonbetweenthe structuresof vuagnatite everysecondlayer(Fig.
andmozartiteshowsthatthesmallreanangementof
the cations and fhe OH goups; therefore,half of theatomic positions, related to the different octahedrally octahedralchains are missing, as comparedwith thecoordinatedcations,modifies slightly the geometryof third category,andthe derivativestructuresresult.
the polyhedra.The meanCa-O distanceis affectedby
AcrNowt-spcEMENTsthe change of the octahedrally coordinated cation,
resultingin an elongationof about0.04A in mozartite.
The replacementofAl by Mn leadsto a changein the
We areindebtedto E. Makovicky,T.B. Zunidandanreviewsandto R.F.
refereefor constructive
varianceof thebondanglesfrom 2O.64to I 1.99for the anonymousThanksaredueto Mr. A.
octahedronandfrom 25.50to 36.00for the tetrahedron. Martin for editorialassistance.
whereasthemeanquadraticelongation(Robinsonera/. Pozzi,localmineralcollector,whoprovideda sampleof1971) doesnotvaryappreciably
for bothpolyhedra.
The mozartite.This studywas supportedby the Ministerotwo mineralsexhibitvery similarmeanSi-O distances dell'Universitd e della Ricerca Scientifica e TecbutratherdifferentindividualSi-Odistances,exceptfornologica.The drawingwas producedwith ATOMS, a
Si-O4. The distancebetweenthe vertices03 and04 of progtamin the ShapeSoftware.
contiguous octahedr4 bridged by the tetrahedron,is
REFERENcES
slightly longerin mozartite,leadingto a wider O3-Si04 angle,togetherwith an unchangedSi-O4 distance
CrystalA. (1989a):
R.,LuccHETn,
G.& PelENzorle,
and a shorter Si-O3 distance;Si-Ol undergoesa BAsso,naturalC2lc
chemical
study
onalographicandcry-stal
Si-O2
contraction balancedby a lengtheningoftheValdi Vara(northem
Na-Mn-clinopyroxenefrom
ordereddistance.
Jahrb'Mineral'Monatsh"59-68'
ltaly)'Neues
Apennines'
The amountof aluminumincorporatedin the crystals
studiedis too smallto ascertainits presence
in tetrahe- --**-*"u,r.n"" & _(1989b):orienrireandmacfallite:
dral coordination.Hence,Al hasbeenassignedto the
Lisuria,mine(eastem
ut tt" Cerchiara
octahedralsite, as in vuagnatite.The mean Mn-O
\aly\.NeuesJihrb.Mineral.Monatsh.,451-460.
distanceandtheelectroneutralityof theformulasuggest
new
Gamagarite:
PeleNzoNe,
thatmanganese
occupiestheoctahedralsiteasMnr*.
-,
A, & Zsnno,L. (1987):
occunence and crystal structure refinement. Neues Jahrb.
Froma topologicalpointof view, mozartiteprovides
M ineral. M onatsh.. 295-3M.
a new exampleof the occurrenceof a structuralmotif
representingthe "backbone"commonto severalcom1989c): Crystal structure refinement& -(pounds(Shen& Moore 1982).Sucha motif, consisting -,of a Sr-bearing term related to copper vanadates andof a linear chainof edge-sharing
octahedrawith conamenatesof adelite and descloizite groups. Neues Jahtb.
nectedtetrahedra
developedalonga 2-fold screwaxis,
M ineral. M onatsh., 300-308.
involvesoctahedrally
coordinated
Mn alongwith tetrahedrallycoordinated
Si in mozartite.FigureI pointsout BusrNc,W.R., Menrn, K.O. & LEVY,H.A. ( 1962):ORFLS, athe two different types of stackingsequenceof tle
FORTRAN crystallographic least-squaresrefi nement program. U.S. Natl. Tech. Inform. Sen. ORNL-TM-3OS.
layers,built up of "backbones"joined by hydrogenbonds,in the structuresof mozartiteand gamagarite(Bassoer al. 1987),mem- CesElLa, R., LuccHErrr. G. & PALENzoNA,A. (1990): Al-rich,
Ba2(F93*,Mn3+)(OHXVO4)2Fe-poor manganoan sugilite in a pectolite-bearing assembers respectively of the third and first of the three
blage from Cerchiara mine (northern Apennines, Italy).
structuralcategoriesproposedby Shen& Moore.The
NeuesJahrb. Mineral. Monatsh., M3448.
stackingsequence
for thestructuresofthethirdcategory,solvedin spacegroupsnr2\2t or Pnma,is fixed by the CEsBRoN,F.P., GtNnr,now, D., GIRAUD,R., PrltssoN, P. &two 2-fold screwaxesorthogonalto the"backbone".In
PILARD, F. (1987): La nickelaustinite Ca(Ni,Zn)(AsOJ(OH): nouvelle espdcemindrale du district cobaltothe resultingarrangementof octahedraand tetrahedra(Fig. la), the uniquetetrahedronnickeliGre de Bou-Azzer, Maroc. Ccut.Mineral.25,401in mozartiteassumes407.
the different roles played by the two independent(Fig. I b), providingbothintratetrahedra
in gamagarite
Gruseppstn, G. & TeotNr, C. (1988): The crystal structure ofandinterchainlinks.
austinite, CaZn(AsOaXOH), from Kamareza, Laurion,
Thechainsofoctahedra,theconnectedterahedraand
Greece.NeuesJahrb. Mineral. Motrcttsh.,159-166.
thelargecationsaremutuallydifferentlydisplacedin thethreecategories,
buttheirtopologyis sufficientlysimilar HAMrLroN, W.C. (1959): On the isotropic temperature factor
to allow for the following structuralrelations.The
equivalent to a given anisotropic temperature factor. Actu
structuresof the first and secondcategorycan be
C tlstcrllogr. 12, 649-610.

336-

THE CANADIAN MINERALOGIST(1965): Significancetests on the crystallographicR
factsf. Acta Crystallngr,18, 502-510.

QuRAsIfl,M.M. & Benrrs, W.H. (1963):The sfiuctureof themineralsofthe descloiziteandadette groups.IV. Descloizite andconichalcite(part2). The stucture ofconichalcite.
Can.Mineral. 7, 561-577.

Lnua-ns-FARrA,J.,
HsuNR, E.,LBAu, F., MAKovrcKy,E. &PARrtS, E. (1990): Nomenclatureof inorganic structure
types.Reportof the InternationalUnion of Crystallography RoBtrlsoN,K", GIBBS,G.V. Rsas, P.H. (1971):&
Quadratic
Commissionon CrystallographicNomenclatureSubcomelongation:a quantiative measureof distortionin cmrdimittee on the nomenclatureof inorganic structuretlpes.
nationpolyhedra-Science172, 567-570.
Aaa Crystallogr.A46, 1-l 1.
Lucccrn, G., ConrusocNo,L. & Palouore, A, (1988):
Low-temperaturemetamorphic mineral assemblagesin
Mn-Fe ores from Cerchiaramine (northem Apennings,
Italy). NeuesJahrb, Mfuvral. MonetslL,367-383.
McNEAR,E., VNcB.n, M.G. & Pann$, E. (1976):The crystal
structureof vuagnatite,CaAl(OH)SiO4.Am" MineraL 6l,
831-838.
NoRrn,A.C.T.,Prflrps, D.C.& Scorr Mamrws, F.S.(1968):
A semi-empiricalmethod of abso'rptioncorrection.Acta
Crystallngr. AU, 351-359.
PABsr, A., ERD,R.C., Gorr, F. & RosHvHAm{,L. (1977):
Vuagnatitefrom Callfornta,MineraL Rec.E,497-501.
PARTITE,
E, & Gu-aro, L.M. (1984): The standardizationof
inorganic crystal-strucure data-Acta Crystallogr. A&,
169-183.

Sanp, H., Bnrnawo, J. & McNBA& E. (1976): Vuagnatite,
CaAl(OlDSiO4,a new naturalcalcium aluminumnesosilicile. ArL Mineral.6l. 825-830,
SHH!, JtrIcHUAN& Moonq P.B. (1982): Tdrnebobmite,
RF2AI(OH)[SiO4]2:crystal structure and genealog5rof
RE(IDSiG!)<+ Ca(tr)P(D isomorphisms.Am. Mineral.
tr|,t021,-t028.
WnrrrAxER, A. (1991): The Magic Flute casc geologicalcorrelations
with Mozart.TerraNwa3.9-16.
YvoN, K., JHrscrtr<o, W. & Penn$, B. (1977): LATYPIILVERX, a computerprogram, for calculatingX-ray
and neutro! ditrraction powder pattem.J. AppL CrysnlIogr, lQ,73-74.
ReceivedMay 20, 1992, revisedmanuscript acceptedOctober 30. 1992.