TY - JOUR
T1 - Crystal chemistry of the low-symmetry (P4nc) vesuvianite from the Kharmankul' Cordon (the South Urals)
AU - Panikorovskii, T. L.
AU - Krivovichev, S. V.
AU - Zolotarev, A. A.
AU - Antonov, A. A.
PY - 2016/1/1
Y1 - 2016/1/1
N2 -
Crystal chemistry of low-symmetry vesuvianite from the Kharmankul' Cordon (in specimen from the Mineralogical Museum of the SPbU) has been studied by electron microprobe analysis, single crystal X-ray diffraction and infrared spectroscopy. The crystal structure have been refined in the Pnc space group (P4nc, a = 15.6218(8), c = 11.8775(6) Å, V = 2898.6(3) Å
3
) to R
1
= 0.036. Chemical composition of investigated sample (wt %): SiO
2
38.22, Al
2
O
3
15.68, MgO 4.03, CaO 37.35, FeO 4.36, total 99.64. The crystal chemical formula can be written as Ca
19
(Al
9.70
Mg
1.48
Fe
1.30
3+
Fe
0.52
3+
)
13
Si
18
O
69
(OH)
9
IR spectrum bands are 438, 476, 563, 607, 632(w), 800, 881, 918, 964, 1016, 3200(shoulder), 3435, 3530 cm
-1
. Different occupancies of the YIa and YIb sites (92 and 8 %, respectively) results in dominant orientation of chains of the intra-channels sites along the c axis, which causes reduction of symmetry from P4/nnc to P4nc. Detected average length of the <Fe-O> bond for YIA position is 1.96 Å, corresponding to Fe
3+
in this position. The mineral-forming took place at temperatures lower that 300°C and the high oxygen fugacity, which is in good agreement with supposed conditions of the contact metasomatic rocks formation in the Kharmankul' Cordon area.
AB -
Crystal chemistry of low-symmetry vesuvianite from the Kharmankul' Cordon (in specimen from the Mineralogical Museum of the SPbU) has been studied by electron microprobe analysis, single crystal X-ray diffraction and infrared spectroscopy. The crystal structure have been refined in the Pnc space group (P4nc, a = 15.6218(8), c = 11.8775(6) Å, V = 2898.6(3) Å
3
) to R
1
= 0.036. Chemical composition of investigated sample (wt %): SiO
2
38.22, Al
2
O
3
15.68, MgO 4.03, CaO 37.35, FeO 4.36, total 99.64. The crystal chemical formula can be written as Ca
19
(Al
9.70
Mg
1.48
Fe
1.30
3+
Fe
0.52
3+
)
13
Si
18
O
69
(OH)
9
IR spectrum bands are 438, 476, 563, 607, 632(w), 800, 881, 918, 964, 1016, 3200(shoulder), 3435, 3530 cm
-1
. Different occupancies of the YIa and YIb sites (92 and 8 %, respectively) results in dominant orientation of chains of the intra-channels sites along the c axis, which causes reduction of symmetry from P4/nnc to P4nc. Detected average length of the <Fe-O> bond for YIA position is 1.96 Å, corresponding to Fe
3+
in this position. The mineral-forming took place at temperatures lower that 300°C and the high oxygen fugacity, which is in good agreement with supposed conditions of the contact metasomatic rocks formation in the Kharmankul' Cordon area.
KW - Cation ordering
KW - Crystal structure
KW - Low-temperature metasomatic rocks
KW - Space group P4nc
KW - The South Urals
KW - Vesuvianite
KW - Vesuvianite group
UR - http://www.scopus.com/inward/record.url?scp=85010891619&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:85010891619
VL - 145
SP - 94
EP - 104
JO - ЗАПИСКИ РОССИЙСКОГО МИНЕРАЛОГИЧЕСКОГО ОБЩЕСТВА
JF - ЗАПИСКИ РОССИЙСКОГО МИНЕРАЛОГИЧЕСКОГО ОБЩЕСТВА
SN - 0869-6055
IS - 3
ER -