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Rediscovery of manandonite in the Sahatany Valley, Madagascar

N. Ranorosoa, F. Fontan and A. M. Fransolet
Rediscovery of manandonite in the Sahatany Valley, Madagascar
European Journal of Mineralogy (October 1989) 1 (5): 633-638


Manandonite occurs as white flakes with a pearly lustre on the (001) cleavage, associated with elbaite and quartz lining vugs of saccharoidal albite, collected in the type locality. The mineral is optically pseudo-uniaxial to biaxial positive, the crystal often twinned on (001) as 6-fold sectors. It is a 1:1 layer silicate and can be considered as a two-layer polytype with a C- centred orthorhombic-shaped cell (a 5.057, b 8.765, c 13.769 Angstrom). A wet-chemical analysis yielded the idealized formula Li (sub 2) Al (sub 4) [(Si (sub 2) AlB)O (sub 10) ](OH) (sub 8) , with Z = 2. The thermal behaviour and the IR spectrum constitute additional features to differentiate manandonite from cookeite.

ISSN: 0935-1221
Serial Title: European Journal of Mineralogy
Serial Volume: 1
Serial Issue: 5
Title: Rediscovery of manandonite in the Sahatany Valley, Madagascar
Affiliation: Serv. Geol., Tananarive, Madagascar
Pages: 633-638
Published: 198910
Text Language: English
Publisher: Schweizerbart'sche Verlagsbuchhandlung (Naegele u. Obermiller), Stuttgart, Federal Republic of Germany
References: 22
Accession Number: 1992-062786
Categories: Mineralogy of silicates
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: 3 tables
S25°40'00" - S11°52'00", E43°00'00" - E50°30'00"
Country of Publication: Germany
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United KingdomTwickenhamUKUnited Kingdom
Update Code: 1992
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