American Mineralogist, Volume 78, pages 425-432, 1993
The redefinition of tengerite-(Y), Yr(CO3)3'2-3H2O, and its crystal structure
Rrrsuno Mrv,q,wA.n
Government Industrial ResearchInstitute, Nagoya, Kita, Nagoya 462, Japan
Juuro
Kunry,q.N{A.,*Izunrr N.c.KAr
Departmentof Chemistry,Universityof Tsukuba,Ibaraki305,Japan
ABSTRACT
Tengerite-(Y) is redefinedas a hydrous yttrium carbonatemineral with an ideal formula
Yr(CO.)..nHrO (n:2-3),
on the basis of reexaminationof the type specimen,type
locality specimens,and synthetic samples.Ca, although previously reported in the literature, is found not to be an essentialcomponent of tengerite-(Y). Tengerite-(Y) is orthorhombic, with space group Bb2rm. The crystal structure of tengerite-(Y) was solved and
refined to R = 0.045 for 765 independent reflections using a hydrothermally synthesized
s i n g l e c r y s t a l . R e f i n e d l a t t i c e p a r a m e t e qr s: 6a .r0e7 8 ( 4 ) , b : 9 . 1 5 7 ( 2 ) , a n d c : 1 5 . 1 1 4 ( 6 )
A, Z :4. The structure can be described as a sheet structure built up from ninefoldcoordinated Y polyhedra and CO. trigonal planar groups. The comrgated sheetsare connected by other CO, groups to form a three-dimensional framework. The structure of
tengerite-(Y)is not related to that of lanthanite-(La) despitetheir compositional similarity.
It is suggestedthat tengerite-(Y) has a close structural relationship to kimuraite-(Y) and
lokkaite-(Y), whereaslanthanite-(La) is related to calkinsite-(Ce).
INrnooucrroN
Tengerite was first described as "carbonated yttrium
earth" by Svanbergand Tenger (1838),and the mineral
name tengeritewas introducedby Dana (1868).Svanberg
and Tenger (1838) reported that the phase occurred as
white pulverulent or fibrous coatings on gadolinite from
Ytterby, northeast of Stockholm, Sweden.Although the
mineral was describedas an yttrium carbonate,no quantitative chemical analysis was made and, of course, no
X-ray diffraction analysiswas provided. The original definition oftengerite was tenuous,and subsequentlyseveral
later specimenswere erroneously reported as tengerite.
The chemical analysis of tengerite from Barringer Hill
(Genth, 1889; Hidden, 1905) indicated the presenceof
considerableamounts of Be. Iimori (1938) gave the
chemical formula YrCa(OH). (CO3)o.3HrO for tengerite
from lisaka, Fukushima, Japan. Stepanov (1961) described a rare-earth carbonate mineral from Kazakhstan
2c rengerite.Vorma et al. (1966) reported a rare-earth
carbonate mineral from Pybrdnmaa, Finland, and provisionally named the mineral tengerite. However, "tengerite" samples from Kazakhstan and Pydrdnmaa were
later found to be new mineral species,namely kamphaugite-(Y) (Raadeand Brasrad, 1993)and lokkaite-(Y) (Perrtunen, l97l). The equivocaldefinitionsoftengeriteresult
from the poor quality of its specimens,which occur as
thin crystalline to powdery coatings.Additionally, in almost all casesit is closely associatedwith other minerals
* Presentaddress:Naka Works, Hitachi Ltd., Ibaraki 312, Japan.
0003-004x/9 3/0304-0425$02.00
from which it cannot be easily separated.Such natural
occurrenceshave made it difficult to analyzethe chemical
composition and crystal structure of tengerite.
Nagashimaand Wakita (1968) and Wakita and Nagashima(1972) synthesizeda hydrous yttrium carbonate
by precipitation from a homogeneoussolution of yttrium
trichloroacetate.Chemical analysisof their synthetic carbonateyielded the chemicalformula Y, (COr)r'rHrO (n
: 2-3).Its X-ray powder diffraction pattern agreedwith
those of tengeritesamplesfrom Iisakar Japan,and RosAs,
Norway (JCPDS 16-698,now replacedby 27-91),and its
IR spectrum was very close to that of the Japanesetengerite. From thesefacts they concluded that the synthetic
product Y, (CO3)3.nHrO and natural tengeritemay have
the same crystal structure.Tareen et al. (1980) have reported the hydrothermal synthesis of single crystals of
Y, (CO3)3.nH,O (n : 2-3), which were practically identical with the substancereported by Nagashima and Wakita (1968).
Perttunen (1971) undertook a reinvestigationoftengerite. He reported that the X-ray powder patterns of
tengerite specimensfrom Pyiirdnmaa and Ldvbdle, Finland, Rosls, Norway (Neumann and Bryn, 1958), and
Iisaka,Japan (Nagashimaand Wakita, 1968),represented one mineral species,whereasthat of "tengerite" from
Kazakhstan (Stepanov, 196l) showed quite a different
pattern from the others. Furthermore,Perttunen(1971)
pointed out that Ca seemedto be an unessentialconstituent in tengerite, according to his X-ray powder diffraction study of synthetic hydrous yttrium carbonate and
chemical analysiswith referenceto the work by Nagashi-
425
ET AL.: TENGERITE-(Y) REDEFINED
MIYAWAKI
TABLE1. List of tengeritespecimensand syntheticsamplesexaminedand resultsof identification
Sample
Locality
Source
ldentifiedmineral species
1
't'
Ytterby
Ytterby
Ytterby
Ytterby
Ytterby
Ytterby
Ytterby
Canada
Askagen
lisaka
lisaka
synthetic
synthetic
synthetic
NaturhistoriskaRiksmuseet,g10820
NaturhistoriskaRiksmuseet,g10820
NaturhistoriskaRiksmuseet,g10821
NaturhistoriskaRiksmuseet,L.K.4133
NaturhistoriskaRiksmuseet,84:0211
SmithsonianInstitution,NMNH R13924
SmithsonianInstitution,NMNH C2248
SmithsonianInstitution,NMNH 97286
Chalmers Universityof Technology
Universityof Tsukuba, NagashimaCollection
SakuraiMuseum
Yr(CO3)3nH,O (hydrothermal,test tube vessel)
Y2(CO3)3
nHrO (hydrothermal,Pyrex tube)
Y"(CO")"r,H,O (gel method)
mixture of lokkaite-{Y)and lanthanite
mixture of kimuraite-(Y)and lokkaite-(Y)
calcite
kimuraite-(Y)
mixture of bastnasite-(Ce)and low quartz
mineralX
kimuraite{Y)
lokkaite-(Y)
mineral X
mixture of mineralX and synchysite
mixture of mineral X and synchysite
synthetic equivalentof mineral X
synthetic equivalentof mineral X
synthetic equivalentof mineral X
2
3
4
5
6
8
o
10
11
12
13
Note.'Mineral X is defined as tengerite-(Y)in this study
ma and wakita (1968). Recently, Raade and Brastad
(1993) have described a new rare-earth mineral, kamphaugite-(Y)lCa,Y,(CO,)o(OH),.2-3H,Ol, found in
Norway, and reported that it is identical with the mineral
from Kazakhstan.
In the present study, a total of ten natural specimens
labeled as tengerite and synthetic crystals of Yr(CO.)..
rHrO sampleswere examined by X-ray powder diflraction, chemical analyses,and IR spectroscopyto redefine
tengerite.Single-crystalX-ray crystal structure analysisof
tengerite-(Y)was carried out to determine the amount of
HrO in the chemical formula, n, andto examine the possible presenceof Ca in the structure. The structural relationships between tengerite-(Y) and other rare-earth
carbonates, such as lanthanite-(La) and kimuraite-(Y),
were also clarified.
This redefinition has been approved in advanceofpublication by the Commission on New Minerals and Mineral Names, IMA. Two neotlpe specimenswere established for tengerite-(Y):one at the SmithsonianInstitution
NMNH, R13924 from the type locality, Ytterby, Sweden,
and one in the Nagashima Collection at the University
of Tsukuba from Iisaka, Japan, now depositedin the National ScienceMuseum of Japan(NSM-M2598l).
RrorrrNrrroN
Specirnens
Specimensexamined in the present study are listed in
Table l. Sample I is regarded as the type specimen (B.
Lindqvist, personal communication). It is A. F. Svanberg's (and C. Tenger's)original material, which, according to notes of J. J. Berzelius, arrived at his museum in
1838.Sample9 is a part of the sampleanalyzedby Iimori
(l 938).
Synthesis
Synthetic sampleswere preparedby the following three
methods. One is a hydrothermal synthesis reported by
Tareen et al. (1980). Concentrated formic acid as a carbonate sourceand an Y(OH), gel, which was obtained by
hydrolysis of an YCl, solution with aqueous ammonia,
were sealedin a Pt capsuleand placed in a test-tube type
stellite vessel.The synthesiswas carried out at 200'C
under a pressure of 340 kg/cm2 for 90 h. The second
method is a synthesisusing a Pyrex glasstube. About l0100 mg of starting rare-earth (Y or La) carbonate was
placed in a Pyrex tube, with a capacity of 3 mL, together
with 0.5 mL of HrO as solvent. The tube was kept at
130-180'C in an electricoven for two weeks.The third
is a gel rnethod using agar or silica gel as a crystal-growth
medium. Three layers, a carbonate-ion source layer, a
diffusion layer, and a rare-earth ion source layer, were
prepared in a glasstest tube. Rare-earth (Y or La) chloride was used for the rare-earth ion source, and ammonium carbonateor sodium hydrogen carbonate was used
for the carbonate ion source. The synthesiswas carried
out at room temperature for l-3 months. Single crystals
of Yr(CO,)r.nHrO (sample1l) suitablefor crystal structure analysis were obtained from the hydrothermal
method.
X-ray powder diffraction analysis
X-ray powder diffraction data of the specimenswere
obtained with a Gandolfi camera using Ni-filtered CuKa
radiation, and some are listed in Table 2. The results
indicated that the white crust on gadolinite-(Y) of sample
I, the type specimen,was a mixture of lokkaite and lanthanite, and the thin coating on gadolinite-(Y) (sample
l') gave a powder pattern that was a mixture of kimuraite
and lokkaite. Two other specimens,samples3 and 6 from
the type locality, also contained thin white coatings on
gadolinite-(Y), and they gave powder patterns similar to
that of kimuraite-(Y). Sample 2 was calcite, and sample
4 was a mixture of bastniisite-(Ce)and quartz. Sample 7,
from Canada, Eavea diffraction pattern that was identical
to that of lokkaite-(Y). Diffraction patterns of samples5,
8, 9, and l0 were identicalto that of syntheticYr(CO3)i'
nHrO (sample 1l), and the minerals are tentatively denoted as mineral X in Table l.
Redefinition
We have found that the museum specimens labeled
tengerite consist of at least five different rare-earth carbonates,including lanthanite (the predominant rare-earth
MIYAWAKI
ET AL.: TENGERITE-ff)
REDEFINED
427
TIaLE2. X-ray powder diffractiondata
Sample11 synthetic
hkt
002
101
111
020
rna
004
113
121
Ulo
564
4.80
4.58
83
100
9
I
7.66
3./U
I
10
10
4.62
10
388
3.78
95
17
3.89
3.77
9
4
3.91
3.82
J.C /
ZJ
J.CC
7
3.59
10
4
8
44
o
64
105
212
131
115
220
006
222
204
125
214
040
2.71
2.70
2.68
2.60
2.53
2.52
2.40
2.37
2.33
2.29
2.29
o
t1
'I
+
2
b
4.60
4.47
390
3.79
I
10
4
10
4
10
4
358
8
345
3.23
8
297
293
I
4
o
2nR
JUO
296
292
l/lo
14.03
10.65
9.03
7.60
I
4
298
'|
2.74
026
141
224
232
107
135
301
2.21
2.12
2.10
2.07
2.04
203
2.01
143
044
206
1.972
1.958
1.939
303
127
321
240
226
1.880
1.859
1.839
1 829
046
244
109
129
147
400
0,0,10
341
246
161
c.04
SamoleI lisaka
l/lo
4.82
4.58
o
304
296
291
288
2.82
145
/ .cJ
l/lo
79
200
123
024
210
JZJ
ooe
Sample 5 Ytterby
1.786,
1.777
1.748
1 739
1.694
1 646
1. 6 1 9
1 526
1 521
1.520
1.51
1. 5 1 0
1.480
1.473
5
-t4
10
36
14
17
'I
1
8
8
26
10
J
3
12
271
2.69
2.60
254
4
2.40
237
2.33
4
z,zJ
q
o
2
A
2.62
255
z
2.38
2.34
2.30
4
2.30
4
2.22
4
2.25
2.21
4
2.13
6br
2.13
o
2.04
2.21
212
2.11
2.07
z
2.O4
5
z.ub
2.01
4
2.03
4
2
1 985
1.953
6
4
13
23
1.939
5
14
16
1.877
1.859
4
4
1.890
1.868
1.830
o
1 841
1.784
o
1.796
2'l
2
19
20
5
o
8
8
2
2
4
1 752
4
1.708
1.661
1 629
1 531
4
2
2
4b(
1.741
I ,OYJ
1.648
1. 6 1 8
5
3
1 523
5br
1.479
4bl
4
I
4
4
1,971
zo
o
2.60
z.c+
2.42
2.39
2.34
JO
IJ
6
2.69
4
4
1.991
1.975
o
o
1.943
1.884
o
I
1.863
4
1.824
6br
1.791
o
| .I4C
o
1.700
o
1. 6 1 6
o
| .czo
6
1
o
4
1.490
Note: br: broad.
element could not be specified),lokkaite-(Y), kimuraiteI and 1', revealed that both are rare-earth carbonates
(Y), bastniisite-(Ce),and a mineral speciesthat has a dif- dominated by Y and are mixtures of lokkaite-(Y) and
fraction pattern identical to synthetic Y, (CO.)r.nHrO. lanthanite (sample l) and kimuraire-(Y) and lokkaite-(Y)
Our identification resultsare summarized in Table l. Our (samplel').
semiquantitative analysis of the type specimens,samples
Of the six Ytterby specimens,only one (sample 5) pro-
ET AL.: TENGERITE-(Y) REDEFINED
MIYAWAKI
428
TABLE3, Chemicalcompositionsof tengeritefrom Ytterby, lisaka,and syntheticsamples
Y.o.
2REErO3
CO,
H.o
Total
0.2
15
0.6
5.1
4.4
n.o.
61
07
o.z
0.7
1.4
0.6
07
0.1
zoJ
54.8
1.2
26.9'..
17.1-'
100
0.007
0.045
0 017
0.147
0.122
0.163
0 018
0 160
0.017
0.035
0014
0.017
0.003
1. 1 3 5
1 900
0 100
2.950
9.162
n.o.
0.1
0.2
1.4
1.6
0.5
4.5
0.9
LO
IJ
3.2
0.3
09
0.1
33.9
JO.J
1.1
28 8.13.6..
100
0.003
0.006
0.038
0 042
0 012
0.112
0.023
0.183
0 030
0.07s
0.008
0.021
0 003
1.356
1.912
0.088
2 956
6.818
S a m p l e1 2
synthetic
No. atoms
(basis
o:9)
o:9)
o:9)
017
0.17
0.09
0.52
0.39
001
1.00
0.22
1.92
0.47
1.46
0.19
1.16
0.16
46.46
54.39
1.79
32.35
13.40
1 0 1. 9 3
Sample13
synthetic
No. atoms
(basis
No. atoms
(basis
No. atoms
(basis
M :2)'
No. atoms
(basis
M :2).
LarO.
Ce,O"
Pr.O.
Nd,o3
Smro3
EurO"
Gdro3
Tbro3
DYro.
Ho,O"
ErrO.
TmrO.
Ybro3
Lu"O.
S a m p l e1 0
lisaka
SampleI
lisaka
Sample5
Ytterby
0.004
0.004
0.002
0013
0.009
0.023
0 005
o 042
0 010
0.032
0.004
o 024
0 003
1.70
1.87
0.13
303
3.07
s4.50--
59 00
32.54
1 1. 1 7
10271
2.94
247
32.90
12.60
r00
1.96
3.03
284
- M : R E E+ C A .
't Calculated.
duced a diffraction pattern conesponding to synthetic
Yr(COr)r.nHrO. Specimensfrom Askagen,Sweden,(sample 8) and Iisaka (samples9 and l0) also gave the same
diffraction patterns. These patterns agree well with that
for the Norwegian tengeritereported in JCPDS 27-91.
The other Ytterby specimensgave patterns representing
various mixtures, including lokkaite-(Y), lanthanite,kiand quartz.
muraite-(Y),calcite,bastnasite-(Ce),
We found that the hydrous yttrium carbonateminerals
from Ytterby, Sweden (sample 5), Askagen (sample 8),
Iisaka,Japan(samples9 and l0), Rosls, Norway (JCPDS
27-91), and Pydrdnmaa,Finland (Perttunen,1971),belong to one mineral species,which is identical to synthetic Y,(COr)r.nH,O (sample 11). Consequently,it is
reasonableto redefine this speciesas tengerite-(Y). The
observed and calculated X-ray powder diffraction data
for the synthetic substancegiven in Table 2 should be
regardedas the standard diffraction data oftengerite-(Y).
Cnrnlrcar- coMPosrrroN
Quantitative analyses of rare-earth elements and Ca
were carried out for the two neotype materials (samples
5 and 9) using a Rigaku 3270E X-ray fluorescenceanalyzer at Osaka Analytical Center, Rigaku Industrial Corporation. A 120-p.gsample was carefully picked under a
microscopeand was dissolvedwith I 20 prl-of lN HNO3.
A 100-p.Lsample of the solution was then dropped on
filter paper (Rigaku drip paper Microcarry 3379C1). The
calibration-curve method combined with the fundamental parameter method using standard solutions was applied to the determination. Corrections were made for
overlap of other analltical lines. Anions compensating
for the plus chargesofthe cations were attributed to the
CO3- ion; i.e., REE,(COr)'and CaCO.. The HrO content was calculatedby difference.The results are given in
Table 3. The resulting cation ratios are reliable, but their
absolutevalues and the HrO content may not be, because
we used an extremely small sample, and we did not directly determine the CO, and HrO contents.
Complete quantitative analysesof natural (sample l0)
and synthetic (samples 12, 13) samples were based on
analysisfor C and H, and on inductively coupled plasma
atomic emission spectroscopic(ICP-AES) analysisfor the
remaining cations. The results are listed in Table 3. The
analysesgave the following empirical formulae for samp l e s 1 0 , 1 2 , a n d l 3 : C a o1 3 R E Er'r C r o . O r ' 3 . 0 7 H r O ,
Y 2 oBC,noos' 2.47H2O,and Y r euc3$O s' 2.84HrO, respectively. The number of HrO molecules rangesfrom 2 to
3, confirming the values reported for synthetic tengerite(Y) (Nagashimaand Wakita, 1968).
Oprrc.q.I, PROPERTIES
Optical properties were measuredusing a fine powder
of sample 5. Tengerite-(Y)is biaxial, n": 1.587 and n"
: 1.616.The calculatedvalue of n for syntheticY, (CO3).'
2H,O (D",.: 3.110g/cm') is 1.620basedon the Gladstone-Dale relationship (Mandarino, I 976).
INrnannn SPECTRA
IR spectrawere measuredon a JascoIR-700 spectrometer using the KBr method. The spectrum of synthetic
tengerite-(Y) indicates characteristic absorptions of carbonateions at l5l0(s), 1463(s),1425(s),867(m),850(m),
840(m), 765(m), 700(m), 690(m) cm ' (s : strong,m :
medium). A broad medium-intensity band resulting from
HrO stretching vibrations appearsin the frequencyrange
MIYAWAKI
ET AL.: TENGERITE-ff)
429
REDEFINED
TABLE4, Atomic positionaland thermalparameters
4.,
c1
c2
o1
02
o3
o4
o5
UO
0.4984(5)
0.256(1
)
0.276(3)
0.332(2)
0 1068(1
0)
0.311(2)
0.473(2)
0.186(2)
0 183(3)
0.34223(s)
0
0 257(3) 0.1957(5)
0 064(2) 0.5
0.129(1) 0.2201(71
0.253(3) 0.1343(4)
0,375(1) 02292(7)
0 012(21 0.s
0 097(2) 0.421(1)
0.414(2) 0 411(1)
4,"
R
v13
10(2) -0.0004(2) -0.0010(1)
0 0 0 6 5 ( 1 ) 0.00243(5) 0.001
0.93'
0 70(11)
1 18.
0.007(4)
0.75(16)
0.82(8)
0.79(17)
1. 1 8 ( 2 0 )
2.08.
0.002(2)
2 28(3s)
0.003(1
)
0 0016(6) -0.001(2)
0 011(2)
0 0026(5)
0.000(1)
a
0 0006(1)
00
0 0006(8) -0.0024(9)
/Vofe.-estimated standard deviationsin parentheses.
. Bq is cafculatedtrom ls(p,.d +
P22U+ Bscs).The anisotropic temperaturefactor form is exp[-(ffP,1 + rcP22+ P1s + 2hkge + 2hlqn + 2klq5ll.
proximate positions of an Y atom and four O atoms,
which were confirmed by the Pattersonmap. Refinement
and difference Fourier synthesisresulted in locating two
additional O atoms and two C atoms. The atomic parameters were refined by least squaresutilizing the program
RFINE2 (Finger, 1969),employing scatteringfactorstaken
Cnysrl,L sTRUCTURE
from Cromer and Mann (1968) and anomalousdisperExperimental
sion factors from the International Tables for X-ray crysThe crystals, hydrothermally synthesizedusing formic tallography(Ibersand Hamilton, 1974).Final cycleswith
yield
acid, have well-developed faces showing orthorhombic anisotropic temperature factors for Y, C2, and 05
: 0.045 (R* : 0.050)for the unrejectedreflectionsand
R
morphology with mmm symmetry. A transparent single: 0 . 1 5 1 ( R * : 0 . 0 5 1 ) f o r a l l r e f l e c t i o n sN. o r e s i d u a l
crystal fragment having dimensions of approximately R
electron
density greaterthan 0.9 e/A'was observedin the
x
x
0.050 0.075 0.125 mm was cut from the synthetic
positional and
crystal and was used for the subsequentX-ray diffraction final differenceFourier map. Final atomic
4. Observed
parameters
in
Table
reported
are
thermal
study. Oscillation and Weissenbergphotographs verified
given
in
Table 5.t
factors
are
structure
calculated
and
that the Laue symmetry is orthorhombic and that the
possiblespacegroups are Bb2tm, Bbnn, or Bbm2. The
Description of the structure
lattice parameters were determined utilizing a Rigaku
The crystal structure of tengerite-(Y) is illustrated in
AFC-5 four-circle automated diffractometer using graphFigure
l. The structure is constructed from comrgated
:
ite-monochromatizedMoKa radiation 0
0.71063 A).
The lattice parameters,obtained by least-squaresrefine- (00 1) sheetsof ninefold-coordinatedY polyhedrain which
the Y polyhedrashareedgesOl-O2 and O2-O3 with the
ment of the 2d values of 25 strong reflections, ate a :
carbonate ion of Cl wedgedbetween the corner-sharing
6 . 0 7 8 ( 4 b) ,: 9 . 1 5 7 ( 2 ) ,c : r 5 . n 4 ( 6 )A , V : 8 4 1 . 2 Q ) k .
A 20-<oscan technique, at a scan rate of 2'lmin, was polyhedra. The sheetsare linkod together at 04 corners
used to measurethe diffraction intensities in one-eighth by the other carbonate ion of C2 to form a three-dimenof a reciprocalsphereup to sin 0/)\: 0.904.The intensity sional framework. The interatomic distances and bond
measurement was repeated twice for a reflection with angles were calculated using UMBADTEA (Finger and
o(lF"l)/lF.l larger than 0.05. The intensities of three Prince, 1975) and are listed in Table 6. The Y atom is
groups
standardreflections,measuredevery 50 observations,did coordinated by eight O atoms of the carbonate
ranging
from
with
Y-O
distances
HrO
molecule,
and
a
not show any fluctuation larger than 3ol0.The data were
planar
ions
carbonate
tne
A.
figonal
2.34(2)
to
2.53(1)
corrected for Lorentz and polarization factors. An abgroup,
O-C-O
In
each
carbonate
distorted.
are
slightly
program
sorption con:ectionwas made using the ACACA
(Wuenschand Prewitt, 1965) in a late stageof the struc- anglessubtendedby the edgesO1-O2 (115.3), O2-O3
polyhedra
ture determination (prr"". : 142.6).A total of 1397 in- ( I 19.8), and O4-O5 (l 17.6) sharedwith the Y
by
subtended
whereas
the
angles
120',
than
are
smaller
dependentreflectionswere obtained, ofwhich 765 reflec(124.4)
(124.8')
and
O5-O5
O1-O3
nonshared
edges
the
'
tions have lF.l
3"(lF"l) and were used in the
are greater than 120'.
subsequentcrystal structure analysis.
of 3500-3000 cm-r, and the H,O deformationband is a
shoulder at 1650(m) cm '. Similar absorptionsare observed in the spectra of the neotype material (sample 5)
and kimuraite-(Y). They are typical of hydrous carbonates.
Structure determination and refinement
Patterson synthesisclearly demonstrated that the true
spacegroup is Bb2rm. An initial model of the structure
was determined by direct methods using the program
Multan-80 (Main et al., 1980).The resultssuggested
ap-
' Table5 maybe obtainedby orderingDocumentAM-93-519
Societyof America,I 130
Office,Mineralogical
from theBusiness
StreetNW, Suite 330, Washington,DC 20036,
Seventeenth
U.S.A.Pleaseremit $5.00in advancefor the microfiche.
430
MIYAWAKI ET AL.: TENGERITE-ff) REDEFINED
The number of HrO moleculesin tengerite-(Y)
Becausepositions of H atoms could not be detectedin
the difference Fourier map, the bond valenceswere calculated according to the procedure of Donnay and Allmann (1970)to revealHrO moleculesites.The 06 atom,
which does not belong to the carbonate groups, is assignedto a HrO molecule on the basisof the bond valence
sum (0.37 vu). The values of the bond valencesums of
05 (1.59 vu) and 06 togetherwith their relatively short
05-06 distances,
2.91(3)and 2.81(3)A, indicaterharrhese
O atoms are involved in H bonding. A correction of the
bond valence sums for H bonds after Donnay and Allmann (1970) gave more ideal values, 1.89 and 0.07 for
05 and 06, respectively, and confirmed the presenceof
H bonds. The H bonds are illustrated by light broken
lines in Figure la. Bond valencesums for other atoms (Y
:2.99; Cl : 3.98C
; 2 : 3 . 9 8O
; l : 1 . 8 4 0; 2 : 1 . 9 5 :
03 : 2.14 04 : 2.12 vu) are in good agreementwith
the expectedformal valence.
The chemical formula of tengerite-(Y) determined by
the present structure analysis is Yr(CO.)r.2HrO. The
number of HrO molecules,two, is smaller than the values
determined by the chemical analysesfor natural and synthetic tengerite-(9, which range between 2 and 3 (see
Table 3). Perttunen(1971)reportedthat much of the HrO
can be lost without any apparent changesin the structure,
basedon checksof the X-ray powder diffraction patterns
of a wet sample and a sampledried at ll0'C. The difference between the number of HrO molecules derived
from the present structure analysis and that determined
by the chemical analysis suggeststhe presenceof zeolitic
H,O in tengerite-(Y), as proposed by Nagashima and
Wakita (1968). The zeolitic HrO moleculesmay be situated in cavities between the corrugated sheets.
Ca content in tengerite-(Y)
Small amounts of Ca were found in our chemical analysis of samples5, 9, and l0 (Table 3). Nagashimaand
Wakita ( 1968)and, later, Perrtunen(197l) suggested
that
Ca seems to be a nonessentialconstituent of tengerite(Y), though many published analysesof natural tengerite(Y) samplesindicated its presence.Attempts at synthesis
ofyttrium carbonatecontaining Ca have been unsuccessful (Nagashima and Wakita, 1968). This was confirmed
by our synthesis experiment. In addition, our crystal
structureanalysisgivesthe formula Y, (CO3)3.2HrO,and
the crystal structure does not support any mechanism for
chargecompensation,which would allow the substitution
ofdivalent Ca for trivalent Y, exceptthrough a deficiency
ofcarbonate ions, which is not probable.
X-ray powder diffraction patterns of samples9 and 10
showed the presence of small amounts of impurities,
mainly synchysite.Therefore, the Ca content detectedin
the above analysesis ascribed to impurities. Tengerite(Y) is known to be an alteration product of rare-earth
minerals such as gadolinite-(Y) and yttrialite-(y); it occurs as fine crystals, closely associatedwith other min-
(b)
(a) A corrugated
Fig. l. Crystalstructureof tengerite-(Y).
sheetat z : 0.25 projectedonto (001);(b) a projectionviewed
down(100)showingthe connectionbetweenthe sheets.
erals. We presume that the Be content or Ca content of
tengeritereported previously must be causedby contamination by associatedminerals. Consequently, the ideal
chemical formula of tengerite-(Y) should be written as
Y, (CO,)r.nH.O (n : 2-3).
Relationship to other hydrous rare-earth
carbonateminerals
The chemical composition of lanthanite-(La),
La, (COr)..8HrO, is closely related to that of tengerite(Y); both minerals are hydrous rare-earth carbonatewith
carbonateto REE ratios of 3:2. Nevertheless,their crystal
structuresare quite different. In contrast to the corrugated
MIYAWAKI
431
ET AL.: TENGERITE.ry) REDEFINED
TABLE
6, Interatomicdistances(A) and bond angles(') with estimatedstandarddeviationsin parentheses
Y-O1
01'
02
2.41(1)
2.53(1)
2.37(3)
2.44(3)
2 36(1)
2.45(1)
2.392(2)
2.42(2)
2.34(2)
n2
ne,
o4
UJ
UO
01-Y-O1',
o1-Y-O2
o1-Y-O2',
o1-Y-O3
o1-Y-O3',
o1-Y-O4
o1-Y-Os
o1-Y-O6
o1',-Y-O2
o1'-Y-O2',
o1'-Y-O3
o1'-Y-03',
o1'-Y-O4
o1'-Y-Os
o1'-Y-O6
79.8(3)
1178(3)
76 1(4)
83.6(4)
64.5(4)
135.5(5)
82.s(5)
1487(s)
135.7(4)
s2 7(3)
64.0(4)
132.0(41
113.6(4)
1301(5)
70 1(s)
02
o3
(A)
Distances
1.31(3)
1 30(1)
1.24(2\
c2-o4
o5
o2-Y-O2'
o2-Y-O3
o2-Y-O3',
o2-Y-O4
o2-Y-O5
o2-Y-O6
o2'-Y-O3
o2'-Y-O3',
02'-Y-O4
o2'-Y-O5
o2'-Y-O6
o3-Y-03',
o3-Y-O4
o3-Y-Os
o3-Y-O6
06-05
os
2.91(3)
2.81(3)
1.29(2)
134(2)x 2
Angles (")
163.1(3)
77.3(4\
54.2(31
83.1(5)
93 7(5)
80.5(5)
11 5 7 ( 3 )
135.7(41
80.1(s)
77.9(51
91.e(6)
80 3(3)
140 9(s)
157.5(5)
75.7(5)
sheetsin tengerite-(Y),the crystal structure of lanthanite(La) (Dal Negro et al., 1977) consistsof platy sheetsparallel to (010). Furthernore, lanthanite-(La)has a free H,O
molecule betweenthe platy sheetsthat is not coordinated
to any cations. The sheetsare connectedonly by H bonding, accountingfor the micaceous{010} cleavage.In the
crystal structure of lanthanite-(La), the rare-earth elements occupy two independenttenfold-coordinated sites.
One rare-earth atom bonds to six O atoms of carbonate
groupsand four O atoms of HrO, and another atom bonds
to eight and two O atoms. On the other hand, the Y atom
in tengerite-(Y) is coordinated by eight O atoms of carbonate ions and one of HrO. Therefore, it may be reasonablethat the formation of these minerals dependson
the ionic radii of the rare-earthelement.Our study showed
that phasesidentical with tengerite-(Y) were synthesized
from the Y rare-earth source,but not from La. Lanthanite-(La) was obtained only from the La rare-earthsource.
Nagashimaet al. (1986) reportedthat there is a correlation between the lattice parametersand the number of
o3'-Y-O4
o3'-Y-O5
o3'-Y-O6
o4-Y-O5
o4-Y-O6
o5-Y-O6
114.3(4)
77.7(51
1324(6)
55.8(5)
67.8(s)
123.6(6)
o1-c1-o2
o1-c1-o3
o2-c1-o3
115.3(21)
124.8(9)
119.8(22)
o4-c2-o5
o5-c2-o5
1 1 76 ( 9 )x 2
124.4(19\
cations of kimuraite-(Y) and lokkaite-(Y) (Perttunen,
l97l). The lattice parametersof tengerite-(Y)are also
related to kimuraite-(Y) and lokkaite-(Y) (Table 7); the a
and b axes of tengerite-(Y) are very similar to c and a of
kimuraite-(Y) and b and c of lokkaite-(9, respectively.
The ratio of the remaining axes c of tengerite-(Y), D of
kimuraite-(Y), and c of lokkaite-(Y) is 15.114(6):
A : 1.92:3.05:5= 2:3:5,which cor23.976(4):39.35(2)
responds to the ratio of the number of cations in each
that theseminerals
chemicalformula, 2:3:5.This suggests
have a close structural relationship and can be classified
in the same mineral group, on the basis of their crystal
structures.
On the other hand, the lattice parameters a and c of
lanthanite-(La) and calkinsite-(Ce) (Pecora and Kerr,
1953)are also closelyrelated(Table 7). Both lanthanite(La) and calkinsite-(Ce)are hydrous rare-earth carbonate
with carbonateto REE ratios of 3:2, REE'(COr)r'nHrO,
and the difference in their chemical formulae is only in
the numbers of HrO molecules;n : 8 for lanthanite-(La),
and calkinsite-(Ce)
lokkaite-(Y),lanthanite-(La),
TABLE7. A comparisonof the crystallographic
data for tengerite-(Y),
kimuraite-(Y),
Tengerite-(Y),'
Y,(CO3)3.2JH'O
Kimuraite-(Y),'CaYr(CO")..6H.O
Bb2.m
a: 6.078(4)
b:9.157(2)
c:15.114(6)
2
l2mm,lmmm,1222,12,2,2,
c: 6.0a$0)
a:9.2s45(8)
b:23.976(41
3
Spacegroup
Cell dimensions(A)
Cations per formula
. Present studyt- Nagashimaet al. (1986).
t Dal Negroet al. (1977).
+ Pecora and Kerr (1953).
Lokkaite-(Y),"
CaY.(CO"),.9H,O
Pb2m, Pbm2, Pbmm
b: 6.104(4)
c:9.26(1)
a: 39.35(2)
5
Lanthanite{La),t
LadCOs)3'8H,O
Pbnb
a : 9.504(4)
c : 8.937(5)
D:16.943(6)
22
Calkinsite-(Ce),+
Ce,(CO").4H,O
n,22,
a:9.57(21
c: 8.94(2)
b:12.65(8)
432
MIYAWAKI
ET AL.: TENGERITE-ff)
REDEFINED
Hidden, W.E. (1905) Some resultsof late minerals researchin Llano
County,Texas AmericanJournalofScience,19,425-433.
Ibers,J.A., and Hamilton, W.C. Eds (1974)Intemationaltablesfor X-ray
crystallography,
vol. IV, p. 148-150.Kynoch Press,Birmingham,U K.
Iimori, T (l 938)Tengeritefound in Iisaka,and its chemicalcomposition
Scientific Papers of the Institute of Physical and Chemical Research
(Tokyo), 34,832-841
Main, P., Fiske, S.J., Hull, S E , lrssinger, L., Germaine, G., Declercq,
J.-P., and Woolfson, M M. (1980) MULTAN-80: A systemof computer programs for the automatic solution of cryslal structures from
X-ray diffraction data Universitres ofYork, U K, and Louvain, Belglum
Mandarino,J.A (1976)The Gladstone-Dalerelationship.I. Derivation
of new constants Canadian Mineralogist, 14, 498-502
Nagashima,K., and Wakita, H (1968)On the compositionof tengerite
Nippon KagakuZasshi,89, 856-859 (in Japanese).
Nagashima,K, Miyawaki, R., Takase,J., Nakai, I , Sakurai,K., Matsubara,S.,Kato, A , and Iwano, S. ( I 986)Kimuraite,CaY, (CO,)o6H,O,
a new mineral from fissuresin an alkali olivine basalt from SagaPreAcxNowr-nocMENTS
fecture,Japan, and new data on lokkaite American Mineralogist, 71,
We wish to acknowledgethe late K. Nagashimaof the University of
t024-]L029
Tsukuba, who called our attention to hydrous rare-earthcarbonates. Neumann,H., and Bryn, K.O (1958)X-ray powderpatternsfor mineral
We are grateful to H Wakita of Fukuoka University, for his informative
identification IV Carbonates,p 6,2O I Kommisjon Hos H. Aschesuggestionson the synthesisoftengerite-(Y) and his encouragementWe
houg,Oslo
thank J.S White, Jr of the Smithsonian Institution, B Lindqvist of the
Pecora,W T, and Kerr, J H (1953)Burbanlcteand calkinsite,two new
Naturhistoriska Riksmuseet in Sweden,K Sakurai of the Sakurai Mucarbonatemineralsfrom Montana AmericanMineralogist,38, I169seum,Tokyo, and A. SvenssonofChalmers University ofTechnology for
I t83
the donation or loan ofthe natural samplesand their advice
Perttunen,V (1971)Lokkaite, a new hydrous RE-carbonatefrom PytiDuring preparationof the manuscript for submissionto the IMA Comrdnmaa pegmatite in Kangasara,SW-Finland Bulletin Commission
mission, many valuable suggestionswere made by E.H Nickel of CSIRO,
G6ologiquede Finlande,43,67-72Australia, and A. Kato of the National ScienceMuseum, Japan, which
Raade,G, and Brastad, K (1993) Kamphaugite-(Y),a new hydrous
are greatly appreciated.We expressour appreciation to G. Raade of the
Ca-(Y,REE)-carbonate
mineral EuropeanJournal of Mineralogy,in
Mineralogisk-Geologisk
Museum, Norway, and J.M. Hughesof Miami
press.
University of Ohro for their comments and suggestionsWe are indebted
Stepanov,A.V. (1961)New and rare mineralsin alkali granitesof Kato N. Nishida and K Imai of the University of Tsukuba for their technical
zakhstan.Trudy KazakhskogoNauchno-Issledova-Tel'skogoInstituta
assistancein the electron microprobe analysisand K Kasai and K YaMineralnogoSyrya,5, 147-16l (in Russran)
mada of Rigaku Industrial Corporation for their technical assistancein
Svanberg,A.F., and Tenger,C (1838)Kolsyrad ytterjord Arsberiittelse
the XRF analysis
om Framstegeni Fysik och Kemi, 16, 206-207 (in Swedish;not seen;
extracted from Dana's System of Mineralogy (7th edition), vol. 2, p
RnpsnnNcrs crrED
2 7 5 - 2 7 6 .t 9 5 1 \ .
Cromer,D.T, and Mann, J.B. (1968)X-ray scatteringfactorscomputed Tareen,J.A.K., NarayananKutty, T.R., and Krishnamurty,K.V. (1980)
Hydrothermal growth of Y,(CO.), nH,O (tengerite) single crystals.
from numerical Hartree-Fock wave functions Acta Crystallographica,
Joumal of CrystalGrowth, 49, 7 6l-765
A24.3Zt-324
Vorma, A., Ojanperti,P., Hoffr6n,V, Siivola,J., and lifgren, A (1966)
Dal Negro,A., Rossi,G., andTazzal,V (1917)The crystalstructureof
On the rare earth minerals from the Pydrdnmaapegmatitein Kangasalanthanite. American Mineralogist, 62, 142-146
la, southeastem-Finland.
Bulletin Commission G6ologiquede FinDana,J.D. (1868)A systemof mineralogy,710 p Wiley, New York.
lande,38, 241-274
Donnay, C , and Allmann, R (1970)How to recognizeO' , OH , and
Wakita, H, and Nagashima,K (1972) Synthesisof tengentetype rare
H.O in cryslal structures determined by X-rays American Mineraloearthcarbonates.
Bulletin ofthe ChemicalSocietyofJapan, 45,2476gist,55,1003-1015.
2479
Finger,L.W (1969)Determinationofcation distributionby least-squares
Wuensch,B J., and Prewitt, C.T. (1965) Correction for X-ray absorption
refinement of single crystal X-ray data Camegie Institution of Washby a crystal of arbitrary shape. Zeitschrift fiir Knstallographie, 122,
ington Year Book, 67, 216-217
24-59.
Finger,L W , and Prince, E (1975)National bureau ofstandards technical
note 854, p. 54-55. U.S Govemment Printing Office, Washington,
DC.
Genth,F.A (1889)Contributionsto mineralogy,no 44. AmericanJourMnNuscnrprRECETvED
Decrlaepn31, l99l
n a l o f S c i e n c e3, 8 , 1 9 8 - 2 0 3 .
MeNuscrrpr AccEprEDNovsusen 9, 1992
ar'd n:4 for calkinsite-(Ce).This suggeststhat calkinsite-(Ce) may have a sheet structure similar to that of
lanthanite-(La).
Consequently,the five minerals described above may
be classifiedinto two mineral groups; i.e., the tengerite
group and the lanthanite group. It is worth noting that
minerals of the former group consist of Y-group rareearths, whereas those of the latter consist of Ce-group
rare-earths.To clarify the relationship between the ionic
radii of rare-earth elements and the crystal structures of
the hydrous rare-earth carbonatesand to substantiatethe
structural relations among theseminerals, structure analysesof kimuraite-(Y) and lokkaite-(Y) are now in progress.