Crystal structures of two new low-symmetry calcium-deficient analogs of eudialyte

Journal Article · Wed Mar 15 04:00:00 EST 2006 · Crystallography Reports

DOI:https://doi.org/10.1134/S1063774506020052· OSTI ID:21091501

Rozenberg, K A; Pekov, I V ^[1]; Chukanov, N V ^[2]; Moeckel, S ^[3]

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1. Moscow State University, Faculty of Geology (Russian Federation)
2. Russian Academy of Sciences, Institute of Problems of Chemical Physics (Russian Federation)
3. Alpha-Geophysik in Sachsen (Germany)

The crystal structures of two new low-symmetry (sp. gr. R3) representatives of the eudialyte group from Mont Saint-Hilaire (Quebec, Canada) and the Lovozero massif (Kola Peninsula, Russia) were studied by single-crystal X-ray diffraction analysis and refined to R = 0.068 and 0.054 using 2899 reflections with F > 5{sigma}(F) and 2927 reflections with F > 3{sigma}(F), respectively. The idealized formulas of these representatives are Na{sub 13}(Ca{sub 3}Mn{sub 3})Zr{sub 3}(Fe, Mn){sub 3}({open_square})(Si)[Si{sub 3}O{sub 9}]{sub 2}[Si{sub 9}O{sub 27}]{sub 2}(O, OH, Cl){sub 3} . 2H{sub 2}O and Na{sub 15}(Ca{sub 3}Mn{sub 3})Zr{sub 3}(Fe, Zr){sub 3}(Si)(Si) . [Si{sub 3}O{sub 9}]{sub 2}[Si{sub 9}O{sub 27}]{sub 2}O{sub 2}(OH, F, Cl){sub 2} . 2H{sub 2}O. Both minerals are analogs of oneillite and are characterized by a low Ca content. The distinguishing features of the mineral from Quebec are that the M(4) site is essentially vacant (>50%) and Ca atoms occupy one independent site in the six-membered ring, whereas another site is occupied by Mn along with a small impurity of Na. In the mineral from the Lovozero massif, both the M(3) and M(4) sites are occupied predominantly by silicon, while Ca atoms are distributed between both octahedral sites of the six-membered ring, one of these sites being occupied predominantly by Mn.

• OSTI ID: 21091501
• Journal Information: Crystallography Reports, Journal Name: Crystallography Reports Journal Issue: 2 Vol. 51; ISSN CYSTE3; ISSN 1063-7745
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CRYSTAL STRUCTURE
IMPURITIES
LOVOZERO
MONOCRYSTALS
QUEBEC
SILICATE MINERALS
X-RAY DIFFRACTION