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The structure of nosean, ideally Na (sub 8) [Al (sub 6) Si (sub 6) O (sub 24) ]SO (sub 4) .H (sub 2) O

Ishmael Hassan and H. Douglas Grundy
The structure of nosean, ideally Na (sub 8) [Al (sub 6) Si (sub 6) O (sub 24) ]SO (sub 4) .H (sub 2) O
The Canadian Mineralogist (June 1989) 27, Part 2: 165-172


The average structure of nosean has been refined in space group P43n to an R of 0.057. The AlO (sub 4) and SiO (sub 4) tetrahedra (present in a ratio 1:1) are fully ordered, but the framework oxygen atoms are positionally disordered over two independent 24(i) sites. The interframework Na cations are located on three independent sets of 8(e) positions that are close to each other on the body diagonals of the cubic structure (sites C1, C2, and C3). The sulphur atom of the SO (super 2-) (sub 4) group is located on the 2(a) site at the centre and corners of the cube, and its oxygen atoms are on an 8(e) site, indicating that the SO (super 2-) (sub 4) group is in one orientation instead of two. The cages contain [Na (sub 4 bullet SO) (sub 4) ] (super 2+) and [Na (sub 4) bullet H (sub 2) O] (super 4+) clusters in a 1:1 ratio, and these clusters are ordered because of net differences in charge and size between them. This cluster ordering also gives rise to antiphase domain boundaries. The space group for each domain is P23, a subgroup of P43n. An 'ideal' nosean structure, modelled in space P23, has several important properties, among which are its uses in the rationalization of the crystal chemistry of nosean and predictions of domains and antiphase domain boundaries.

ISSN: 0008-4476
EISSN: 1499-1276
Coden: CAMIA6
Serial Title: The Canadian Mineralogist
Serial Volume: 27, Part 2
Title: The structure of nosean, ideally Na (sub 8) [Al (sub 6) Si (sub 6) O (sub 24) ]SO (sub 4) .H (sub 2) O
Affiliation: McMaster Univ., Dep. Geol., Hamilton, ON, Canada
Pages: 165-172
Published: 198906
Text Language: English
Publisher: Mineralogical Association of Canada, Ottawa, ON, Canada
References: 21
Accession Number: 1989-082109
Categories: Mineralogy of silicates
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 5 tables
Country of Publication: Canada
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United KingdomTwickenhamUKUnited Kingdom
Update Code: 1989
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