American Mineralogist, Volume 67, pages 1035-103E,1962
Konyaite, NazMg(SO4)2 . 5H2O, a new mineral frorn the Great Konya Basin, Turkey
JeN D. J. ver.{ Doessunc, Lroprg
VsncouwBN
AND LBeNoBRt veN oBn PLns
Department of Soil Science and Geology, Agricultural University
Duivendaal 10, Wageningen, The Netherlands
Abstract
Konyaite, NazMg(SOq)2.5H2O,
a new mineralfound in the Great Konya Basin, Turkey,
is associatedwith one or more of the following minerals:bloedite, hexahydrite,gypsum,
starkeyite, halite and loeweite. Synthetic single crystals of konyaite are transparent,
euhedralprismaticwith a platy habit flattenedon {010}and elongatedparallelto {10T}.fhe
mineralismonoclinic,P2llc,witha:5.784(3),b:24.026(9),c:8.066(3)A,B:95.37(3)",
4.541(l00xl2l),
Z = 4. Strongestlines in the X-ray powder pattern are: 12.01(40X020),
D (meas.)of synthetic kon4.202(40)(12l),4.017(45)(002),
3.960(45)(012),2.597(45)(240).
yaiteis 2.038(6)
g/cm3;D(calc.)is 2.097g/cm3.Konyaiteis biaxial(-); refractiveindicesa
: | .464(l),B : I .468(I ) and 7 : 1.474(r\; 2Y : 74(2)",2V(calc.) : 79o; a ll b : ylrc : 7}Qt" .
Konyaite is metastablewith respectto bloedite.DTA-TG curvesshow four endothermsat
about 80, 92,124 and237'C due to dehydration.In additiona smallexothermis presentat
about 325"C. The name is for the localitv.
This basin is situated on the Central Anatolian
m and is filled
The new mineral konyaite was first observedon Plateauat an altitude of about 1000
(de Meester,
marl
soils
with
saline
clayey
mainly
X-ray powder patterns during a study of salt miner1970).
als from the Great Konya Basin in Turkey. After
The basin is bordered on the north by the Anatosubtraction of the diffraction lines of the associated
lides,
consistingof Paleozoic schists and igneous
minerals,37 distinct lines remainedthat could not
rocks
covered by Mesozoic limestones.Devonian
be matched with any of the minerals in the Powder
limestonesand schistsand
Permocarboniferous
and
Diffraction File of the rcpns. Further study on
and
ultrabasic rocks form its
limestones
Cretaceous
syntheticmaterialproved theselines to belong to a
of Miocene, Pliocene
Volcanics
border.
southern
singlecrystallinephase.In this context it shouldbe
in composition from
varying
age,
and
Quaternary
stressedthat due to the minute size of the konyaite
the basin.Most
in
and
around
occur
to
acidic.
basic
crystals and the intimate intergrowth with associathas no natural
which
into
the
basin,
flowing
rivers
ed minerals all the data and most of the crystallomountains.
the
Taurus
from
come
outlet.
graphic data are derived from analysesof synthetic
Salts originate at the soil surface by evaporation
material.The new mineral is namedkonyaite ('konground and surface waters. These salts consist
of
yii-it) after the type locality which is in the Great
mainly
of sulphates and chlorides of sodium and
Konya Basin in Turkey along the road from Erelli
(Vergouwen,1981).Konyaite occurs in
magnesium
to Nilde near the village of Qakmak. Type material
in the following assemblages:
the
effiorescences
is depositedat the National Museum of Geology
gypsum,hexahydrite,bloedite; konyaite,
konyaite,
and Mineralogy, Hooglandse Kerkgracht 17, Leibloedite,gypden,The Netherlands.As this mineral is metastable bloedite,halite, starkeyite;konyaite,
gypsum, hexahydrite; konkonyaite,
sum,
halite;
with respectto bloedite, it is to be expectedthat it
will changeto bloedite with time. The description yaite, loeweite, hexahydrite.
and the namewere approvedby the Commissionon
Chemicalcompositionand synthesis
New Minerals Names IMA, prior to publication.
Becausemost minerals which occur in associaOccurrence
tion with konyaite contain NazSO+and/or MgSOa
Konyaite has been found in salt effiorescenceson and semi-quantitativetests proved Na, Mg and SO+
saline soils in the Great Konya Basin in Turkey. to be essentialit was consideredlikely that konyaite
1035
r0-l 035$02.00
0003-004x82/09
Introduction
1036
VAN DOESBURG ET AL.: KONYAITE
also containsthese components.It was found that
konyaite could be synthesizedby evaporationof a
solution containingNa2SOaand MgSOain a molar
ratio of 1:1 in a watch-glass at a temperature
between 30 and 50" C. In this manner a white
powder consisting of pure konyaite was formed.
Below 30oC, thenardite, epsomiteand sometimes
mirabilite formed in addition to konyaite. Above
50'C loeweite and bloedite formed in addition to
konyaite. Well-shapedcrystals of konyaite (maximum size about 3 x 0.5 x 0.02 mm) formed from
evaporationofa saturatedsolution at 35'C using a
secondlarger watch-glassas a cover glass. White
powdery salt consistingof pure konyaite formed on
the rim of the watch-glass,and transparentsingle
crystalsformed in the center.The chemicalanalysis
of synthetickonyaiteis given in Table l. Na and Mg
were analyzedby meansof atomic absorptionspectrometry; SOaby meansof gravimetricanalysisand
the water content was determined with TG. The
averageof two analysesleads, after normalization
to 100%o
and on the basisof O : 8, to the empirical
formula Na2.63Mgy.6r(SO4)2.00.5.02H2O
or ideally
Na2Mg(SOa)2.5H2O.
days. Unground samplestransformedmore slowly.
The large single crystals did not transform after six
months.In addition,powderedsamplesof synthetic
konyaitewere alteredwhen placedin desiccatorsat
room temperature with 0, 20, 50 and 80%orelative
humidity respectively.After six weeks all desiccators contained samples which were completely or
partly transformed to bloedite. It can be concluded
that konyaite is metastablewith respect to bloedite
at room temperature. Grain-size is an important
factor in this transformation.
X-ray crystallography
The X-ray powder diffraction data for both natural and synthetic konyaite were obtained with a
Guinier camera,equippedwith a Johanssonmonochromator, CoKal X-radiation and corundum as
internal standard.The completedata, includingthe
calculatedd values and indices, are listed in Table
2. The d values of natural konyaite and synthetic
konyaite agree well. Refinement of the X-ray powder diffraction data of synthetic konyaite using the
computer program of Visser (1969) shows that
konyaite is monoclinic with unit-cell parameters a
: 5.784(3),b : 24.026(9),c : 8.066(3)Aand B :
Chemical stability
95.37(3)".Refinementof the X-ray powder diffracKonyaite is a very unstable mineral. It was tion dataof naturalkonyaiteleadsto a : 5.786(3),b
identified in the samples taken from the Konya : 24.029(9),c : 8.060(3)Aand F : 95.38(3)'.In
Basin within three months after sampling. Two addition, the unit-cell parameters were determined
years later in some samples konyaite was still for synthetic konyaite using rotation, precession
presentbut in others it could no longer be identi- and WeissenbergX-ray photographs. These also
fied. Powderedsynthetickonyaite decomposednot show that konyaite is monoclinic. The unit-cell
only by further heating at the temperature of syn- parameters,after transformation,area : 5.79(l), b
thesis,but also at room temperature.In both cases :24.04(2), c : 8.07(l)Aand p: 95.4(2)".
Extincit transformed, at least partly, to bloedite in a few tions of I f 2nfor hOlreflections and k f 2n for 0k0
reflections uniquely determine the space group as
PZ/c.The completecrystallographicdata are listed
in Table 3.
Table l. Chemical analysesof synthetic konyaite
Optical and physical properties
Na
1 3. 0 6
AJ.
Iq
13.10
1 3 .0 5
Mo
6.99
6.89
6,94
6.90
qn
5 3 .9 3
54. 14
5 4 .0 4
54.51
H^0
25.25
Zf,.OJ
25.4+
25.54
TotaL
9 9 .2 3
99.80
9 9 .5 2
1 , 2 : slmthetic konyaite (wt.?).
3l
average of 1 and 2.
4:
t h e o r e t i c a l N a r M g ( S O U ) r5. H r 0 .
1 0 0. 0 0
Konyaite is optically biaxial negative;the refractive indicesared.: 1.464(l),B: 1.468(l)and 7 :
1.474(l); 2Y : 74(2)" and 2Y(calc) : 79'; the
orientationis ct ll b and /\c : 70(2).The hardness
(Mohs) is estimatedto be 2.5; konyaite is readily
solublein water. The averagedensity measuredon
six differentrosettesof konyaite (: 10mg each)by
the heavy-liquidmethod, using a mixture of bromoform and phthalic acid dibutyl ester, is 2.088(6)
dcmt, in excellent agreementwith the calculated
value of 2.097 glcm3on the basis of Z : 4.
1037
VAN DOESBURG ET AL.: KONYAITE
Table 2. X-ray powder diffraction data for konyaite
qrrh+h6+
Natural'
a
ODS
72.00
7 .610
i ^
Natwal'
-calc
d.
I/I
ODS
O
5.756
5,662
5.192
40
8
<2
4
4
4
12,013
7.616
6.007
5.759
5 .671
5. 193
020
011
040
100
031
L20
+. 809
4.806
15
4. 810
4.803
4.6?5
+.539
4.409
4.202
041
111
130
L2L
1"11
L2L
4.179
4. 014
4. 005
3.957
4.67't
4. 541
4.409
4.202
<2
100
35
40
4. 180
4.017
4.002
3.960
3.916
3.797
20
45
20
3.592
3.592
20
3.431
3.4t3
3.448
3,434
3.413
3.337
6
6
20
10
3.314
3,282
3.156
3.315
3.278
3.156
6
10
3.L29
3 . 13 0
3.101
15
3.080
2.988
8
20
2.937
2.887
2.855
8
<2
<2
2.8L2
2.834
2.872
I
8
2.800
2.801
20
2.778
L0
3.079
2.988
<2
4
4. 181
4.015
4.004
3.960
3.913
3.798
131
002
060
0L2
131
141
3.594
3.589
3.449
3.432
3.414
3.338
141
o32
LO2
151
LT2
042
3.315
3.279
3.1s8
3. 156
L22
15 t_
L02
J.
fJA
O
2.724
15
2.7rO
2. 6 5 9
2.7LO
2.659
4
40
2.63'7
2.539
40
2.6Lr
4
2.597
2.572
45
4
2.558
2,532
<2
<2
2.504
<2
2.479
4
2.469
<2
2.443
<2
2.432
2.432
2.415
I
6
2,\02
2.402
20
2 , 4 ' ,97
LL2
IOI
3. 0 8 1
2.991
2.987
2, 9 3 8
2.879
2. 8 5 9
052
142
161
L32
200
2L0
2.835
2. 8 1 3
2.872
2.802
2.800
2.776
062
081
L7T
L52
220
2tI
Thermal analysis
-calc
r tf
ODS
07r
3.101
+ Lines not resolved from lines of associated
.
visually.
Intensities
estimted
** Calcul-ated on basis of nonoclinic
cell with
Svnthetic
..-.-.---.-_----T
A
ODS
L2.OL
7.62L
6.005
5.759
5.674
5.195
4. 539
4.413
r + .1 9 9
+
A
2.337
2.323
are onitted.
a=5.784,
b=24.026,
I7L
22L
230
180
013
152
2.639
2.613
2.613
2. 6 0 9
2 .5 9 6
2.572
23i.
023
toz
072
240
2 .5 6 1
2 .s 3 4
2.533
2. 5 0 5
2.s01
2,480
181
24t
091
113
23L
]-62
2.470
2.466
2.445
2. 4 3 8
2.433
2.4L6
250
L23
043
2t2
r72
2.4r2
2,405
2,403
2,403
2.402
2.338
24L
082
0.1_0.0
222
260
053
113
L'12
143
25L
L23
0.10.1
242
133
2.323
I
2.309
2.300
<2
<2
2.338
2,334
2.324
2.323
2,309
2.302
2.270
2.250
2
<2
2.302
2.269
2.250
Plus 66 observed lines
minerals
2.726
2.722
2.7L0
2.663
2.660
2.639
to
1.468A with
22r
I/Io<10.
c=8.066A and B=95.37'.
from room temperatureto375" C. The DTA and TG
curves are shown in Figure 1. The DTA curve is
The thermal analyseswere performedwith a Du characterized by four endotherms and one small
Pont990ThermalAnalysis Systemusinga DSC-cell exotherm.From severalanalysesit appearsthat the
and a 951 thermal balance. About 15 mg of pow- peak temperatureof the first endotherm varies. The
dered synthetickonyaite was weighedin an alumi- peak temperatures of the four endotherms are
num samplepan covered with a pierced lid. Al2O3 80*10"C. 92-14"C. 124-+3'Cand 237+2"C rewas used as reference material. DTA and TG were spectively. The peak of the exotherm is at
carried out in an atmosphere of static air with a 325-+2'C.
heating rate of 5" C/min and temperature ranging
The TG and DTA curves show that all endo-
1038
VAN DOESBURG ET AL.: KONYAITE
Table 3. Crystallographic data for konyaite
Synthetic
a(A)
b
5.79(1)24,04(2)
Synthetic
Natlr]]al
s . 7 8 4 (3 )
s.786(3)
24.026(9)
24.029(9)
8.07(1)
8.066(3)
8.060(3)
I
s s . 4 (2 )
95.37(3)
e s . 3 8 (3 )
V ( A ")
1118(2)
Crystal
systen:
ftIo.
u( 5,
u
t
I
u
r,r.r-s.7(s)
Monocfinrc
Space group: P2rlc
Cefl contents:
4 NarMg(SOu)2.5H2O
Density(calc) : 2.097 g/cm3
R
10
Density(meas): 2,088(6) g/cm3
,r From single-crystal
techniques.
** Fr:ornrefinement of X-nay powden diffraction
data,
+ Estimated standard deviations in parentheses refen
to the Last decimal place.
therms are due to dehydration. The weight losses
after the three dehydration steps (there are actually
four, but the first two are not well resolved) are
4.90, 9.25 and 11.29%respectively. The first two
per€entagesagree well with the theoretical weight
loss of 5.1I and 9.48Vofor the transitionof konyaite
to bloediteand the transitionof bloediteto loeweite
respectively,which were identified as intermediate
products. The last two endotherms are due to
dehydration of bloedite and this part of the dehydration curve is in agreement with the result of the
thermal study of bloedite by Madsen (1966).The Xray powder patterns of the crystalline products
before and after the exotherm are different. Both
patterns could not be matched with any pattern in
the Powder Diffraction File of JcpDs.
Acknowledgments
The authorsthankMss. J. M. A. R. Weversfor the precession
photographs and Mr. E. L. Meijer for running the computer
program and for many helpful suggestions.Mr. P. G. M. Ver-
o
7zo
o
100
300
200
^
T e m p e r a t u r "eC
,
Fig. l. TG, DTG and DTA curvesof synthetickonyaitein an
atmosphereof static air. Heating rate: 5' C/min
steeg prepared Figure I and Mrs. C. B. Beemster typed the
manuscript.
References
Madsen,B. M. (1966)Loeweite, vanthoffite,bloedite,and leonite from southeasternNew Mexico. U.S. GeologicalSurvey
ProfessionalPaper, 550-8, 125-129.
de Meester,T. (1970)Soils of the Great Konya Basin, Turkey.
Pudoc,Wageningen,the Netherlands.
Vergouwen, L. (1981) Mineralogical composition and origin of
salt effiorescencesin the Konya basin, Turkey and in Kenya.
Neues Jahrbuch fiir Mineralogie, 1, 23-34.
Visser, J. W. (1969)A fully automatic program for finding the
unit cell from powder data. Journal of Applied Crystallography, 2, 89-95.
Manuscriptreceived,August 5, 196l;
acceptedfor publication, March 2, 1962.