Information card for entry 9001998

Structure parameters

• Mineral name: Fluoro-eckermannite
• Formula: Cr0.76 F2 Mg4.42 Na2.51 O22 Si8
• Calculated formula: Cr0.76 F2 Mg4.42 Na2.51 O22 Si8
• Title of publication: Unusual M3+ cations in synthetic amphiboles with nominal fluoro-eckermannite composition: Deviations from stoichiometry and structural effects of the cummingtonite component Sample: Cr2, Na1.00Na1.75Mg.25Mg4.25Cr.75Si8O22F2
• Authors of publication: Oberti, R.; Hawthorne, F. C.; Camara, F.; Raudsepp, M.
• Journal of publication: American Mineralogist
• Year of publication: 1999
• Journal volume: 84
• Pages of publication: 102 - 111
• a: 9.728 Å
• b: 17.825 Å
• c: 5.278 Å
• α: 90°
• β: 103.66°
• γ: 90°
• Cell volume: 889.326 ų
• Number of distinct elements: 6
• Space group number: 12
• Hermann-Mauguin space group symbol: C 1 2/m 1
• Hall space group symbol: -C 2y
• Has coordinates: Yes
• Has disorder: No
• Has Fobs: No