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Kayrobertsonite, MnAl (sub 2) (PO (sub 4) ) (sub 2) (OH) (sub 2) .6H (sub 2) O, a new phosphate mineral related to nordgauite

Stuart J. Mills, Ian E. Grey, Anthony R. Kampf, William D. Birch, Colin M. Macrae, Jason B. Smith and Erich Keck
Kayrobertsonite, MnAl (sub 2) (PO (sub 4) ) (sub 2) (OH) (sub 2) .6H (sub 2) O, a new phosphate mineral related to nordgauite (in The 8 (super th) European conference on Mineralogy and spectroscopy, Giovanni Andreozzi (editor), Ferdinando Bosi (editor) and Francesco Di Benedetto (editor))
European Journal of Mineralogy (June 2016) 28 (3): 649-654


Kayrobertsonite, MnAl (sub 2) (PO (sub 4) ) (sub 2) (OH) (sub 2) .6H (sub 2) O, is a new secondary phosphate mineral from the Hagendorf Sud pegmatite, Hagendorf, Oberpfalz, Bavaria, Germany and the Foote Lithium Company mine, Kings Mountain district, Cleveland County, North Carolina, USA. Kayrobertsonite crystals occur as intergrown masses of snow-white, soft, finely fibrous needles, less than 5 mu m in diameter and no more than 100 mu m in length. Quantitative analysis of Foote mine kayrobertsonite gave the empirical formula: Mn (sub 0.97) Ca (sub 0.03) Fe (sub 0.02) Al (sub 1.87) (PO (sub 4) ) (sub 2) (OH) (sub 1.62) F (sub 0.03) (H (sub 2) O) (sub 0.38) .6H (sub 2) O; and for Hagendorf Sud kayrobertsonite: Mn (sub 0.92) Ca (sub 0.06) Fe (sub 0.02) Al (sub 1.87) (PO (sub 4) ) (sub 2) (OH) (sub 1.19) F (sub 0.42) (H (sub 2) O) (sub 0.39) .6H (sub 2) O. Foote mine kayrobertsonite crystals are biaxial (-), with indices of refraction alpha = 1.530(1), beta = 1.554(1), gamma = 1.566(1), measured in white light; 2V(meas.) is 70.3(5) degrees , while 2V(calc.) is 69.6 degrees . The mineral is nonpleochroic. The orientation of the crystals is Z approximately c (length slow). Kayrobertsonite is triclinic, space group P1, with the unit-cell parameters: a = 10.049(2), b = 10.205(2), c = 6.083(1) A, a = 91.79(3), b = 99.70(3), g = 98.02(3)A, V = 607.9(2) A (super 3) and Z = 2 (Foote mine). The polyhedral framework in kayrobertsonite has the same topology as that in nordgauite, but with replacement of F by OH at the bridging anion sites. The main crystal chemical change from nordgauite to kayrobertsonite is a doubling of the number of water molecules in the [001] channels.

ISSN: 0935-1221
EISSN: 1617-4011
Serial Title: European Journal of Mineralogy
Serial Volume: 28
Serial Issue: 3
Title: Kayrobertsonite, MnAl (sub 2) (PO (sub 4) ) (sub 2) (OH) (sub 2) .6H (sub 2) O, a new phosphate mineral related to nordgauite
Title: The 8 (super th) European conference on Mineralogy and spectroscopy
Author(s): Mills, Stuart J.Grey, Ian E.Kampf, Anthony R.Birch, William D.Macrae, Colin M.Smith, Jason B.Keck, Erich
Author(s): Andreozzi, Giovannieditor
Author(s): Bosi, Ferdinandoeditor
Author(s): Di Benedetto, Francescoeditor
Affiliation: Museum Victoria, Geosciences, Melbourne, Victoria, Australia
Affiliation: Sapienza University of Rome, Rome, Italy
Pages: 649-654
Published: 201606
Text Language: English
Publisher: Schweizerbart'sche Verlagsbuchhandlung (Naegele u. Obermiller), Stuttgart, Germany
Meeting name: 8th European conference on Mineralogy and spectroscopy
Meeting location: Rome, ITA, Italy
Meeting date: 20150909Sept. 9-11, 2015
References: 10
Accession Number: 2016-085343
Categories: Mineralogy of non-silicates
Document Type: Serial Conference document
Bibliographic Level: Analytic
Illustration Description: illus. incl. 7 tables
N35°12'40" - N35°12'40", W81°21'20" - W81°21'20"
N49°39'01" - N49°39'01", E12°27'34" - E12°27'34"
Secondary Affiliation: Commonwealth Scientific and Industrial Research Organisation, AUS, AustraliaNatural History Museum of Los Angeles County, USA, United States
Country of Publication: Germany
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Abstract, copyright, Schweizerbart'sche Verlagsbuchhandlung. Reference includes data from GeoScienceWorld, Alexandria, VA, United States
Update Code: 201641
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