Published November 1981 | Version v1
Journal article

Symmetry and twinning of boltwoodite

  • 1. Technische Univ. Berlin (Germany, F.R.)

Description

The results of the X-ray and chemical analyses of boltwoodite from namibia are presented. The chemical analysis showed a considerable amount of sodium besides potassium, thus it is possible that there exists sodium boltwoodite with the molecular ratio K2O:Na2O=2:1. Potassium and sodium are partially replaced with H3O. The idealized formula is (K, Na)sub(2-x)(Hsub(3)O)sub(x)x[UOsub(2)SiOsub(4)]xHsub(2)O, the symmetry is monoclinic, sp.gr. is Csub(2h)sup(2)=P2sub(1)/m, a=6.65, b=7.07, c=7.11 A, β=105 deg 30', Z=2. The acicular crystals are stretched along [010] with rather good cleavage along 001. The cleavage plane is (anti 101). A very close resemblance to kasolite is pointed out

Additional details

Additional titles

Original title (Russian)
Симметрия и двойникование больтвудита

Publishing Information

Journal Title
Kristallografiya
Journal Volume
26
Journal Issue
6
Series
Kristallografiya.
Journal Page Range
1288-1292
ISSN
0023-4761

Optional Information

Notes
For English translation see the journal Soviet Physics - Crystallography (USA).