Published 1985 | Version v1
Journal article

Uranyl and aluminum phosphates from Kobokobo. VII. Moreauite, Al3UO2(PO4)3(OH)2.13H2O, new mineral

  • 1. Musee Royal de l'Afrique Centrale, Dept. de Geologie et de Mineralogie, Tervuren (Belgium)
  • 2. Laboratoire de Chimie Physique et de Cristallographie de l'Universite, Louvain-la-Neuve (Belgium)

Description

Moreauite (pronounce moro-ait) occurs at Kobokobo (Kivu, Zaire) as nodules and as piles of small tablets which are flattened on (100) and sometimes elongated along b. Bright greenish yellow in color, translucid to opaque. Monoclinic, P21/c with a=23.41, b=21.44, c=18.34 A and β = 92.00. Z=16. Density: 2.64 (measured) and 2.61 g/cm3 (calculated). The strongest lines of X-ray powder pattern are: 10.8(100) 020, 11.69 (80) 200, 9,13 (70) 002, 2.93 (70) 206, 14.02 (60) 011 and 3.043 (60) 106. Optically biaxial negative with 2V = 700. nsub(z)=1.558, nsub(y)=1.552 and nsub(x)=1.540. Optical orientation: X approximately a*, Y=b and Z approximately c. Strong fluorescence under UV lights. Chemical composition: Al2O3 17.2%, UO3 32.8%, P2O523.0%, H2O 27.0%. Formula: Al3UO2(PO4)3(OH)2.13H2O. Associations: uranyl and aluminum phosphates and particularly furongite and ranunculite. The name in honour of the Belgian mineralogist Jules Moreau

Abstract (French)

La moreauite provient du gisement de Kobokobo, Kivu, Zaire. Le mineral se presente sous forme de nodules ou d'empilements de fines plaquettes aplaties sur (100) et parfois allongees selon b. La couleur est jaune verdatre vif; le mineral est translucide a opaque. Systeme monoclinique P21/c avec a=23,41, b=21,44, c=18,34 A et β = 92.00. Z=16. Densite=2.64 (mesuree) et 2,61 (calculee). Les raies les plus intenses du diagramme de poudre sont: 10,8 (100) 020, 11,69 (80) 200, 9,13 (70) 002, 2,931 (70) 206, 14,02 (60) 011 et 3,043 (60) 106. Le mineral est biaxe negatif, 2V=700. nsub(g)=1,558, nsub(m)=1,552 et nsub(p)=1,540. Orientation optique: X approximativement a*, Y=b et Z approximativement c. Fortement fluorescent aux UV. Composition chimique Al2O3 17,2%, UO3 32,8%, P2O5 23,0%, H2O 27,0%. Formule: Al3UO2(PO4)3(OH)2.13H2O. Associations: phosphates d'uranyle et d'aluminium et, particulierement, furongite et ranunculite. Le nom en l'honneur du mineralogiste belge Jules Moreau

Additional details

Additional titles

Original title (French)
Les phosphates d'uranyle et d'aluminium de Kobokobo VII. La moreauite, Al

Publishing Information

Journal Title
Bull. Mineral.
Journal Volume
108
Journal Issue
1
Series
Bull. Mineral.
Journal Page Range
9-13
ISSN
0180-9210