TY - JOUR
T1 - Khurayyimite Ca7Zn4(Si2O7)2(OH)10·4H2O
T2 - a mineral with unusual loop-branched sechser single chains
AU - Krüger, Biljana
AU - Galuskina, Irina O.
AU - Galuskin, Evgeny V.
AU - Vapnik, Yevgeny
AU - Murashko, Mikhail N.
N1 - Publisher Copyright:
© 2022, The Author(s).
PY - 2023/6/1
Y1 - 2023/6/1
N2 - The new mineral khurayyimite Ca7Zn4(Si2O7)2(OH)10·4H2O occurs in colorless spherulitic aggregates in small cavities of altered spurrite marbles located in the northern part of the Siwaqa pyrometamorphic rock area, Central Jordan. It is a low-temperature, hydrothermal mineral and is formed at a temperature lower than 100 °C. Synchrotron single-crystal X-ray diffraction experiments have revealed that khurayyimite crystallizes in space group P21/c, with unit cell parameters a = 11.2171(8), b = 9.0897(5), c = 14.0451(10) Å, β = 113.297(8)º, V = 1315.28(17) Å3 and Z = 2. The crystal structure of khurayyimite exhibits tetrahedral chains of periodicity 6. The sequence of SiO4 and ZnO2(OH)2-tetrahedra along the chain is Si–Si-Zn. The neighboring SiO4-tetrahedra of the corrugated chains are bridged by additional ZnO2(OH)2-tetrahedra to form 3-connected dreier rings. The chains can be addressed as loop-branched sechser single chains {lB, 11∞}[6Zn4Si4O21]. The chains are linked by clusters of five CaO6 and two CaO7 polyhedra with additional OH groups and H2O molecules in the coordination environment. Based on the connectedness and one-dimensional polymerisations of tetrahedra (TO4)n−, chains of khurayyimite belong to the same group as vlasovite Na2ZrSi4O11, since they can be described with geometrical repeat unit cTr = 2T43T4 and topological repeat unit cVr = 2V23V2.
AB - The new mineral khurayyimite Ca7Zn4(Si2O7)2(OH)10·4H2O occurs in colorless spherulitic aggregates in small cavities of altered spurrite marbles located in the northern part of the Siwaqa pyrometamorphic rock area, Central Jordan. It is a low-temperature, hydrothermal mineral and is formed at a temperature lower than 100 °C. Synchrotron single-crystal X-ray diffraction experiments have revealed that khurayyimite crystallizes in space group P21/c, with unit cell parameters a = 11.2171(8), b = 9.0897(5), c = 14.0451(10) Å, β = 113.297(8)º, V = 1315.28(17) Å3 and Z = 2. The crystal structure of khurayyimite exhibits tetrahedral chains of periodicity 6. The sequence of SiO4 and ZnO2(OH)2-tetrahedra along the chain is Si–Si-Zn. The neighboring SiO4-tetrahedra of the corrugated chains are bridged by additional ZnO2(OH)2-tetrahedra to form 3-connected dreier rings. The chains can be addressed as loop-branched sechser single chains {lB, 11∞}[6Zn4Si4O21]. The chains are linked by clusters of five CaO6 and two CaO7 polyhedra with additional OH groups and H2O molecules in the coordination environment. Based on the connectedness and one-dimensional polymerisations of tetrahedra (TO4)n−, chains of khurayyimite belong to the same group as vlasovite Na2ZrSi4O11, since they can be described with geometrical repeat unit cTr = 2T43T4 and topological repeat unit cVr = 2V23V2.
KW - Dreier rings
KW - Loop-branched sechser chains
KW - New mineral
KW - Topology
UR - http://www.scopus.com/inward/record.url?scp=85145084600&partnerID=8YFLogxK
U2 - 10.1007/s00710-022-00804-z
DO - 10.1007/s00710-022-00804-z
M3 - Article
AN - SCOPUS:85145084600
SN - 0930-0708
VL - 117
SP - 191
EP - 200
JO - Mineralogy and Petrology
JF - Mineralogy and Petrology
IS - 2
ER -