Nambulite, (Li,Na) Mn4Si5O14(OH), in the Sausar Group of rocks in central India

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doi: 10.2465/jmps.100.26
Authors:Mukhopadhyay, Subir; Das, Kaushik; Fukuoka, Masato
Author Affiliations:Primary:
Jadavpur University, Department of Geological Sciences, Kolkata, India
Presidency College, India
Hiroshima University, Japan
Volume Title:Journal of Mineralogical and Petrological Sciences
Source:Journal of Mineralogical and Petrological Sciences, 100(1), p.26-30. Publisher: Mineralogical Society of Japan and the Japanese Association of Mineralogists, Petrologists and Economic Geologists, Sendai, Japan. ISSN: 1345-6296
Publication Date:2005
Note:In English. 8 refs.; illus., incl. 2 tables
Summary:Manganese carbonate-silicate rocks in the Sausar Group, India are often traversed by pegmatite veins. Nambulite, a lithium- and sodium-bearing hydrous manganosilicate, is formed by the reaction of a hydrothermal solution with the host mineral, rhodonite. Despite the similarity of natronambulite and nambulite, the chemical composition shows a variation in the concentration of Na+ in the empirical formula: (Li0.94-0.60 Na0.06-0.40)Σ1.00(Mn3.57-3.82 Ca0.13-0.07 Mg0.36-0.07 Fe0.03-0.01)Σ3.96-3.86Si5.01-4.98O14(OH)1.00. This is the first report of the sodium-rich variety from India. Powder X-ray diffraction studies reveal the unit cell parameters of nambulite in the triclinic system as a = 7.55±0.06 Å, b = 11.77±0.07 Å, c = 6.68±0.04 Å, α = 91.3°±0.8°, β = 95.4°±0.5°, γ = 107.2°±0.7° and V = 563±6 Å3.
Sections:Crystal structure
Subsections:Specific structures: silicates
Subjects:Archean; Chain silicates; Chemical composition; Electron probe data; Granites; Igneous rocks; Pegmatite; Plutonic rocks; Precambrian; Rhodonite; Rhodonite group; Sausar Series; Silicates; X-ray diffraction data; Central India; Nambulite
Abstract Numbers:07M/3807
Record ID:2005076088
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute.
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