- journal_title：American Mineralogist
- Contributor：Evelyne M.S. Leduc ; Ronald C. Peterson ; Ruiyao Wang
- Publisher：Mineralogical Society of America
- Date：2009-
- Format：text/html
- Language：en
- Identifier：10.2138/am.2009.3132
- journal_abbrev：American Mineralogist
- issn：0003-004X
- volume：94
- issue：7
- firstpage：1005
- section：Articles
The crystal structure of synthetic konyaite, Na2Mg(SO4)2·5H2O, a = 5.7690(8), b = 23.951(3), c = 8.0460(11) Å, β = 95.425(2)°, V = 1106.8(3) Å3, space group P21/c, Z = 4, was solved using single-crystal X-ray diffraction. Hydrogen atom positions were determined and the structure solution was refined to R1 = 3.31% and wR2 = 6.28% for the 2167 measured independent reflections. Three distinct cation sites host the Mg and Na atoms in distorted octahedra and eight-coordinated polyhedra. The coordination polyhedra share edges to form compact sheets oriented perpendicular to b and linked to one another by hydrogen bonds. This results in a {010} tabular habit. A comparison of this structure is made to that of blödite [Na2Mg(SO4)2·4H2O], the dehydration product of konyaite. Konyaite is discussed within the context of the Na2O-MgO-SO4-H2O system. This study is part of ongoing investigations into the dehydration mechanisms and phase stability of this system.