A possible new mineral species ferrogate

720

A POSSIBLE NEW MINERAL SPECIES, “FERROGATEHOUSEITE”
(Fe,Mg)5(PO4)2(OH)4 FROM CONTU PEGMATITE, ROMÂNIA
1906

IGR

1

2

2

1

1

2

N. CALIN , A-M. FRANSOLET , M. BAIJOT , S. MARINCEA , D-G. DUMITRAS , F. HATERT ,

1
1
M.A. ANASON , A.M. IANCU
1. Department INI, Geological Institute of Romania, 1 Caransebes Str. , RO-012271, Bucharest, Romania,
nicolae_cln@yahoo.com
2. Université de Liège, Laboratoire de Minéralogie, B18, Sart Tilman, 4000, Belgique.
phosphate

Gatehouseite, Mn5(PO4)2(OH)4, is a rare Mn-bearing
phosphate, since this mineral is only reported in a
sedimentary iron ore deposit in Australia (Pring and
Birch, 1993). Like in many Mn-bearing phosphates
structures, Fe may replace Mn and a complete solid
solution often exists between the Mn- and Fe-bearing
end-members. One more time, our work leads us to
consider the existence of an hypothetic new species,
“ferrogatehouseite”, which would be the iron
dominant equivalent species of gatehouseite.

quartz


phosphate

muscovite
muscovite

albite

feldspar

albite

quartz

feldspar

muscovite
quartz
muscovite


phosphate

phosphate

Hand specimens of pegmatites from Contu

During the research on the Li-bearing pegmatites from
Contu (Cibin Mountains, South Carpathians, Romania) a
rich phosphate association, including heterosite –
purpurite, lithiophilite – triphylite, sicklerite –
ferrisicklerite, fluorapatite, vivianite, monazite, wolfeite
was identified. Other associated minerals include
spodumene, quartz, muscovite, K-feldspar, plagioclase,
beryl, cassiterite, columbite group minerals, lepidolite,
rutile, scarce schorl, uraninite, topaz, spessartine,
sillimanite, titanite. Pegmatites from Contu are hosted
by micaschists and gneisses related to the Sebes - Lotru
Series.

0


50

1 = schists and muscovite-bearing gneisses;
2 = kyanite schists; 3 = staurolit schists;
4 = garnet-bearing schists;
5 = amphibolites, gneisses and schists;
6 = pegmatites quartzo-feldspathic;
7 = albite and spodumene-bearing pegmatites;
8 = graphic pegmatites.

100Km

Geological map of Romania

Table 5. Unit-cell parameter for heterosite
Sample
N 113
N 107 b
29 B

N 109
N 114 A
N 128
Ci_1d
Ce. 1C
Ce. 2D
N 129
N 122
N 120
Mean

Table 1. Unit-cell parameters for triphylite
Sample
a(Å)
b(Å)
c(Å)
23C1
4,719(1)
10,368(6)
6,035(5)

65CI
4,718(4)
10,366(3)
6,031(2)
9E
4,712(4)
10,379(6) 6,039(10)
29B
4,718(1)
10,378(3)
6,033(4)
Ci 1D
4,712(8)
10,375(7)
6,047(6)
Ci 1D1
4,713(7)
10,380(6)
6,038(7)
Mean

4,715(4)
10,374(5)
6,037(6)
Sabau et.al. (1990)
4,698(4)
10,365(5)
6,034(9)
Anderson et al. (2000) 4.6908(2) 10.3290(3) 6.0065(2)
Losey et al. (2004)
4,7138(6) 10,3826(1) 6,0499(5)

To achive this the goals of this work, a series of analytical
methods were used as follows:(1)optical study with Leica and
Jenapol-U polarizing microscopes; (2) X-ray powder diffraction
using a Bruker D8 Advance diffractometer (Ni-filtred Cu Ka
radiation,  = 1.54060Å, accelerating voltage 40 Kv, beam
current 40 mA); (3) electron-microprobe analyses, using
CAMECA SX 50 device in wavelength-dispersive mode.

P2O5

FeO
MnO
MgO
CaO
Li2O
Total 1
Total 2
Triphylite

Phosphates belonging to the triphylite - lithiophilite series
generally occur as nests in the spodumene and feldspar
masses. They from granular masses of greenish gray
color that turns locally into dark or black, due to the
weathering. Both optical and scanning electron microscope
studies show that triphylite abundantly contains inclusions
of wolfeite and of a gatehouseite - like phase, the later
occurring on the (001) perfect cleavage plane of triphylite.

P2O5
FeO

MnO
MgO
CaO
Li2O
Total 1
Total 2
Triphylite

X-ray powder data were obtained on a representative sample
and indexed according to ICDD file 01-070-0516, belonging
to gatehouseite. These data allow the refinement of the
unit-cell parameters, in the space group P212121(19). The
refined parameters are: a = 9.103(3) Å, b = 18.019(6) Å and
c = 5.685(9) Å. The a and b parameters are slightly larger
while c is slightly smaller compared to those of gatehouseite,
given by Pring and Birch (1993), i.e., a = 9.097(2) Å,
b = 18.002(3) Å and c = 5.693(2) Å.

P
Fe2+

Mn
Mg
Ca
Li
Triphylite
P
Fe2+
Mn
Mg
Ca
Li

Sample
N 103
Ce 59
23C1
N 112
Mean
ICDD 00-033-0802


a(Å)

b(Å)

c(Å)

5,945(6)
5,941(7)
5,943(9)
5,945(4)
5,944(7)
5,946

10,076(8)
10,061(5)
10,056(8)
10,061(9)
10,064(8)
10,063

4,793(1)
4,791(8)
4,796(2)
4,797(7)
4,794(5)
4,793

Ferrisicklerite

9/c2
10/c2
11/c2
19/c4
20/c4 39/c12 40/c12
%
%
%
%
%
%
%
45.94
45.98
45.79
45.93
46.51
46.26
46.18
30.73
30.9
30.46
30.23
30.8
29.64
29.45
15.04
15.14
15.23
15.21
15.1
15.65
16
0.3
0.28
0.29
0.24
0.25
0.25
0.25
0.01
0.04
0.02
0.06
0.04
0.07
0.04
9.66
9.66
9.62
9.64
9.64
9.70
9.70
92.02
92.34
91.79
91.67
92.7
91.87
91.92
101.68 102.00 101.41 101.31 102.34 101.57 101.62
94/c9 159/c1 160/c1 161/c1 166/c1 167/c1 171/c1
%
%
%
%
%
%
%
46.14
46.11
46.11
46.07
45.31
46.59
46.12
30.88
29.29
29.29
29.32
26.38
26.75
26.45
15.31
16.82
16.82
16.6
19.47
19.37
19.26
0.29
0.14
0.14
0.14
0.06
0.07
0.06
0.04
0.04
0.04
0.03
0.05
0.03
0.03
9.69
9.68
9.69
9.68
9.51
9.79
9.69
92.66
92.4
92.4
92.16
91.27
92.81
91.92
102.35 102.08 102.09 101.84 100.78 102.60 101.61
9/c2
1PO4
1
0.660
0.327
0.011
0
0.999

10/c2
1PO4
1
0.663
0.329
0.010
0.001
0.998

11/c2
1PO4
1
0.657
0.332
0.011
0
0.998

19/c4
1PO4
1
0.65
0.331
0.009
0.001
0.997

20/c4
1PO4
1
0.654
0.324
0.009
0.001
0.998

39/c12
1PO4
1
0.633
0.338
0.009
0.001
0.995

40/c12
1PO4
1
0.63
0.346
0.009
0.001
0.997

94/c9
1PO4
1
0.660
0.332
0.011
0.001
0.998

159/c1
1PO4
1
0.627
0.364
0.005
0.001
0.998

160/c1
1PO4
1
0.627
0.364
0.005
0.001
0.998

161/c1
1PO4
1
0.628
0.360
0.005
0
0.998

166/c1
1PO4
1
0.575
0.429
0.002
0.001
0.997

167/c1
1PO4
1
0.567
0.416
0.002
0
0.998

171/c1
1PO4
1
0.566
0.419
0.002
0
0.998

P2O5
FeO
MnO
MgO
CaO
Li2O
Total 1
total 2
Ferrisicklerite
P2O5
FeO
MnO
MgO
CaO
Li2O
Total 1
total 2

42/c1
43/c1
47/c1
56/c3
57/c3
59/c3
60/c3
71/c6
%
%
%
%
%
%
%
%
44,67
43,95
43,28
45,14
44,54
43,98
42,87
41,79
30,00
31,03
30,17
30,69
30,94
30,9
31,68
32,11
18,83
18,78
19,61
18,36
18,49
18,73
19,36
19,72
0,10
0,11
0,1
0,1
0,11
0,11
0,11
0,11
0,52
0,37
0,66
0,28
0,29
0,36
0,46
0,53
9,13
9,06
8,76
9,35
9,22
9,07
8,78
8,52
94,12
94,24
93,82
94,57
94,37
94,08
94,48
94,26
103,25 103,30 102,58 103,92 103,59 103,15 103,26 102,78
72/c6
79/c7
81/c7 84/c10 125/c9 158/c1 174/c6 175/c6
%
%
%
%
%
%
%
%
45,13
43,3
44,14
44,31
42,93
45,21
43,66
42,56
30,65
31,13
30,39
30,77
30,15
29,76
29,42
30,12
18,58
18,96
18,71
18,65
19,77
17,74
19,71
20,04
0,09
0,12
0,12
0,1
0,09
0,15
0,08
0,06
0,25
0,74
0,44
0,38
0,27
0,79
0,42
0,53
9,37
8,72
9,20
9,13
8,89
9,10
8,97
8,68
94,7
94,25
93,8
94,21
93,21
93,65
93,29
93,31
104,07 102,97 103,00 103,34 102,10 102,75 102,26 101,99

Ferrisicklerite
P
Fe
Mn
Mg
Ca
Li
Ferrisicklerite
P
Fe
Mn
Mg
Ca
Li

42/c1
PO4
1
0,663
0,421
0,003
0,014
0,970

43/c1
PO4
1
0,697
0,427
0,004
0,010
0,978

47/c1
PO4
1
0,688
0,453
0,003
0,019
0,961

56/c3
PO4
1
0,671
0,406
0,003
0,007
0,984

57/c3
PO4
1
0,687
0,415
0,004
0,008
0,983

59/c3
PO4
1
0,693
0,426
0,004
0,010
0,979

60/c3
PO4
1
0,729
0,451
0,004
0,013
0,973

71/c6
PO4
1
0,758
0,472
0,004
0,015
0,968

72/c6
PO4
1
0,670
0,411
0,003
0,006
0,986

79/c7
PO4
1
0,710
0,438
0,004
0,021
0,957

81/c7
PO4
1
0,679
0,424
0,004
0,004
0,990

84/c10
PO4
1
0,685
0,421
0,003
0,010
0,978

125/c9
PO4
1
0,693
0,460
0,003
0,007
0,984

158/c1
PO4
1
0,650
0,392
0,005
0,021
0,956

174/c6
PO4
1
0,665
0,451
0,003
0,012
0,975

175/c6
PO4
1
0,699
0,471
0,002
0,015
0,968

a(Å)
b(Å)
c(Å)
9,100(7) 17,992(9) 5,702(8)
9,098(3) 18,017(3) 5,688(2)
9,103(3) 18,019(6) 5,685(9)
9,110
18,032
5,692
9,097(2)
18,002
5,693(2)

P2O5
Fe2O3
Mn2O3
MgO
CaO
Total
Heterosite
P2O5
Fe2O3
Mn2O3
MgO
CaO
Total
Heterosite
P
Fe3+
Mn3+
Mg
Ca
Heterosite
P
Fe3+
Mn3+
Mg
Ca

44/c1
%
46,65
33,09
20,33
0,11
0,23
100,41

45/c1
%
45,42
33,16
20,58
0,08
0,33
99,578

48/c1
%
46,75
31,95
19,99
0,12
0,38
99,19

58/c3
%
46,85
32,70
19,90
0,11
0,28
99,85

61/c3
%
46,87
32,76
20,018
0,07
0,23
99,95

62/c3
%
46,79
33,47
19,38
0,10
0,35
100,09

63/c3
%
47,19
33,17
20,10
0,07
0,18
100,72

64/c3
%
47
33,18
19,70
0,08
0,17
100,14

65/c3
%
46,14
33,16
20,60
0,06
0,27
100,24

70/c6
%
46,25
32,69
19,52
0,1
0,53
99,10

74/c7
%
47,08
32,24
19,49
0,09
0,59
99,49

75/c7
%
47,42
32,72
19,50
0,09
0,42
100,16

76/c7
%
46,21
32,26
19,18
0,08
0,52
98,25

77/c7
%
47,69
33,15
19,57
0,09
0,16
100,66

78/c7
%
47,17
32,58
19,38
0,09
0,29
99,51

80/c7
%
47,22
33,36
19,85
0,09
0,14
100,66

83/c10
%
46,27
34,61
19,72
0,09
0,14
100,84

149/c1
%
44,95
31,49
19,55
0,14
2,01
98,14

153/c1
%
45,63
32,35
18,90
0,12
0,58
97,58

44/c1
1PO4
1
0,630
0,391
0,004
0,006

45/c1
1PO4
1
0,649
0,407
0,003
0,009

48/c1
1PO4
1
0,607
0,384
0,004
0,010

58/c3
1PO4
1
0,620
0,381
0,004
0,007

61/c3
1PO4
1
0,595
0,368
0,002
0,005

62/c3
1PO4
1
0,635
0,372
0,003
0,009

63/c3
1PO4
1
0,624
0,383
0,002
0,004

64/c3
1PO4
1
0,627
0,377
0,003
0,004

65/c3
1PO4
1
0,638
0,401
0,002
0,007

70/c6
1PO4
1
0,628
0,379
0,003
0,014

74/c7
1PO4
1
0,608
0,372
0,003
0,015

75/c7
1PO4
1
0,613
0,369
0,003
0,011

76/c7
1PO4
1
0,620
0,373
0,003
0,014

77/c7
1PO4
1
0,617
0,368
0,003
0,004

78/c7
1PO4
1
0,614

80/c7
1PO4
1
0,627

83/c10
1PO4
1
0,665

149/c1
1PO4
1
0,622

153/c1
1PO4
1
0,630

13/c4
14/c4
15/c4
16/c4
17/c4
18/c4
120/c6
121/c6
122/c6
124/c6

Ca0,009 (Fe3,083 Mn1,855 Mg0,021)4,959 (PO4)2 (OH)4
Ca0,004 (Fe2,877 Mn2,030 Mg0,053)4,960 (PO4)2 (OH)4
(Fe2,793 Mn2,117 Mg0,055)4,965 (PO4)2 (OH)4
Ca0,0018 (Fe2,9631 Mn1,9575 Mg0,0355)4,9562 (PO4)2 (OH)4
Ca0,0034 (Fe2,7353 Mn1,7171 Mg0,0424)4,4949 (PO4)2 (OH)4
(Fe2,9897 Mn1,9335 Mg0,0237)4,9470 (PO4)2 (OH)4
Ca0,0047 (Fe3,7168 Mn1,2523 Mg0,0265)4,9956 (PO4)2 (OH)4
Ca0,0028 (Fe3,6019 Mn1,3550 Mg0,0247)4,9818 (PO4)2 (OH)4
Ca0,0009 (Fe3,5570 Mn1,3776 Mg0,0382)4,9730 (PO4)2 (OH)4
Ca0,0018 (Fe3,5819 Mn1,3569 Mg0,0250)4,9640 (PO4)2 (OH)4

te
l eri

Table 9. Representative electron-microprobe analysis of ferrogatehouseite
(FeMn)5(PO4)2(OH)4

albite

fe rr
k
isic

albite

c(Å)
4.765(4)
4.773(6)
4.768(9)
4.770(3)
4.777(2)
4.772(3)
4.783(6)
4.773(2)
4.773(2)
4.776(2)
4.773(6)
4.782(8)
4.774(4)

Table 8. Chemical structural formulas of
ferrogatehouseite

k
isic
albite

Heterosite

Table 7. Unit-cell parameters for gatehouseite

f err

Electron-microprobe analyses of this mineral, identified as iron-rich
gatehouseite (sample 14/c4), yielded (in wt.% oxides): P2O5 = 26.76, FeO
albite
= 38.97, MnO = 27.15, MgO = 0.41, CaO = 0.05, H2O (calculated for charge
balance) = 6.79, total =100.13. The crystal-chemical formula which
results from this composition is: (Fe2.877Mn2.030Mg0.053Ca0.004)(PO4)2(OH)4,
which is related to the one of gatehouseite but with Fe > Mn. Chemical
analyses on two other samples yielded similar empiric formulae, i.e.,
(Fe3.083Mn1.855Mg0.021Ca0.009)(PO4)2(OH)4 and (Fe2.735Mn1.717Mg0.042Ca0.003)
ferrisicklerite
(PO4)2(OH)4 (samples 13/c4 and 17/c4, respectively).

P2O5
Fe2O3
Mn2O3
MgO
CaO
Total

P
Fe3+

albite
ferrisicklerite

Heterosite

Heterosite

Sample
23 C1
10 C
Ci 58 F
ICDD 01-070-0516
Pring and Birch (1993)

b(Å)
9.765(5)
9.749(4)
9.757(8)
9.756(6)
9.748(1)
9.718(7)
9.758(3)
9.742(4)
9.778(6)
9.811(9)
9.775(2)
9.763(1)
9.76(5)

Table 6. Representative electron-microprobe
analysis of heterosite

Table 4. Representative electron-microprobe
analysis of ferrisicklerite

Table 2. Representative electron-microprobe
analysis of triphylite
Triphylite

Table 3. Unit-cell parameters for ferrisicklerite

a(Å)
5.841(9)
5.829(2)
5.837(4)
5.835(3)
5.824(3)
5.833(6)
5.810(5)
5.810(4)
5.844(5)
5.857(1)
5.824(9)
5.821(3)
5.830(5)

te
l eri

Further investigations by FTIR and micro-Raman are needed to acquire
albite
more details about the H2O content of this potential ferrous homologue
of gatehouseite. The petrographic texture indicates that
“ferrogatehouseite” as well as wolfeite, partially replaced triphylite
Photomicrograph of ferrisicklerite in
along its cleavage plane during the hydrothermal stage.
association with feldspars. Plane polarized

13/c4

14/c4

15/c4

16/c4

17/c4

18/c4

120/c6

121/c6

122/c6

124/c6

%

%

%

%

%

%

%

%

%

%

P2O5

26,6

26,76

26,81

26,73

29,05

26,69

26,54

26,58

26,71

26,69

FeO

41,51

38,97

37,91

40,09

40,22

40,39

49,93

48,46

48,09

48,39

MnO

24,66

27,15

28,37

26,15

24,93

25,79

16,61

18

18,39

18,1

MgO

0,16

0,41

0,42

0,27

0,35

0,18

0,2

0,187

0,29

0,19

CaO

0,1

0,05

0

0,02

0,04

0

0,05

0,03

0,01

0,02

H2O

6,75

6,79

6,80

6,78

7,37

6,77

6,73

6,74

6,77

6,77

Total 1

93,03

93,34

93,51

93,26

94,59

93,05

93,33

93,26

93,49

93,39

total 2

99,78

100,13

100,31

100,04

101,96

99,82

100,06

100,00

100,27

100,16

2PO4

2PO4

2PO4

2PO4

2PO4

2PO4

2PO4

2PO4

2PO4

2PO4

P

2

2

2

2

2

2

2

2

2

2

Fe

3,083

2,877

2,793

2,963

2,735

2,989

3,716

3,601

3,557

3,581

Mn

1,855

2,030

2,117

1,957

1,717

1,933

1,252

1,355

1,377

1,356

Mg

0,021

0,053

0,055

0,035

0,042

0,023

0,026

0,024

0,038

0,025

Ca

0,009

0,004

0

0,001

0,003

0

0,004

0,002

0,000

0,001

H2O

4

4

4

4

4

4

4

4

4

4

light. Crossed nicols.

triphylite
triphylite

triphylite

triphylite
“ferrogatehouseite”

ferrogatehouseite

ferrogatehouseite

“ferrogatehouseite”
Photomicrograph of triphylite sample with inclusion of
ferrogatehouseite. Plane polarized light. Crossed nicols.

Back-scattered image
of ferrogatehouseite in triphylite.

Photomicrograph of ferrogatehouseite
( 30 µm in length, 20µm in width) on cleavage .

References:
ANDERSSON, A. S., KALSKA, B., HÄGGSTRÖM, L. and THOMAS, J. O. (2000): Lithium extraction/insertion in LiFePO4:
An X – ray diffraction and Mössbauer spectroscopy study. Solid State Ionics, 130, 41 – 52.
LOSEY, A., RAKOVAN, J. and HUGHES, J. M., FRANCIS, C. A., DYAR, M. D. (2004): Structural variation in the
lithiophilite – triphylite series and other olivine group structures. The Canadian Mineralogist, Vol. 42, pp.
1105 – 1115.
PRING, A., AND BIRCH, W. D. (1993): Gatehouseite, a new manganese hydroxy phosphate from Iron Monarch,
South Australia. Mineral. Mag., 57, 309 – 313.
SABAU, G., ILINCA, G., MARINCEA, S., ROBU, L. (1990): Evaluation of the lithium potential of the Romanian
pegmatites and of the possibilities of use. I. South Carpathians (Cibin Mountains). Unpubl. Report,
Geological Institute of Romania, 65 pp.

Acknowledgements
This research was supported by the Executive Agency for Higer Education, Research,
Development and inovation Funding (UEFISCDI), Ministry of National Education in Romania,
through the projects IDEI PN-II-ID-PCE-2013-3-0023 and ERA-MIN PT 339, 25.03.2014.

ferrisicklerite
heterosite
quartz

heterosite

ferrisicklerite

Photomicrograph showing the association ferrisicklerite - heterosite - quartz.
Heterosite has an obvious pleochroism in tints of mauve and yellow, whereas ferrisicklerite has more
evident pleochroism in tents.