Home > Mineral Abstracts > CanMin Vol. 9, pp. 585-596 (1969)




Vol. 9, pp. 585-596 (1969)



La lemoynite, un nouveau silicate hydraté
de zirconium et de sodium de
St. Hilaire, Québec

(Lemoynite, a new hydrated zirconium and sodium silicate
from St. Hilaire, Québec)


Guy Perrault, E.I. Semenov, A.V. Bikova et T.A. Capitonova

ABSTRACT

     Lemoynite has the following chemical composition:

SiO2 - 47.32%
ZrO2 - 23.23%
TiO2 - 0.43%

Nb2O5 - 2.18%
REE2O3 - 1.18%
Fe2O3 - 1.61%

MnO - 0.10%
CaO - 5.06%
Na2O - 4.75%

H2O - 13.33%
Total - 99.19%



     The following formula agrees with this analysis:
(Na,Ca)3Zr2Si8O22 · 8H2O. Nx = 1.540, Ny = 1.553, Nz = 1.570,
Z ^ a = 5°, 2Vobs = 80°, 2Vcalc = 83°, optic sign +, positive elongation.

     The space group belongs to the C* aspect (probably C2/m): a = 10.48 Å, b = 16.20 Å, c = 9.07 Å, b = 105°20', Z = 2, rmeas = 2.29,  rcalc = 2.26.

     The five most intense lines on the x-ray powder pattern are:

8.01 Å at 100
3.562 Å at 49
2.807 Å at 48

9.0 Å at 37
3.034 Å at 33


     Lemoynite occurs in pegmatites of the St-Hilaire alkaline massif; it probably belongs to the hydrothermal phase. The name is after Charles Lemoyne, lord of Longueuil, and his celebrated sons; all well-known personalities in French-Canadian history.




© 1969  The Canadian Mineralogist