Vol. 18, pp. 85-88 (1980)
Paranatrolite, a new zeolite from
Mont St-Hilaire, Québec
George Y. Chao
Department of Geology, Carleton University,
Ottawa , Ontario K1S 5B6
Vol. 18, pp. 85-88 (1980)
Mont St-Hilaire, Québec
Department of Geology, Carleton University,
Ottawa , Ontario K1S 5B6
ABSTRACT
Paranatrolite, a new zeolite from Mont St-Hilaire, Québec, is unstable in air and dehydrates to form tetranatrolite. Unaltered paranatrolite has been observed only as colorless transparent epitactic overgrowths on natrolite crystals preserved in water since the time of collection. Physical properties are : H = 5-5½, D(obs) = 2.21 g/cm3; fracture conchoidal; cleavage, unobserved. The mineral is pseudo- orthorhombic, diffraction aspect, F***, with a 19.07(1), b 19.13(1), c 6.580(3) Å, Z = 8. The true symmetry is probably monoclinic, perhaps triclinic. The diffraction spots are very diffuse, suggestive of a disordered structure. The strongest Gandolfi diffraction lines are:
The powder pattern is similar to that of gonnardite. Optically the mineral is biaxial negative, 2V < 10°, with low birefringence and oblique extinction. The chemical formula is that of tetranatrolite except for the water content, which is calculated from the mass-density-volume relationship: (Na1.75Ca0.40>K0.09)Fe0.01Al1.95Si3.02O10 · 2.98H2O.
Keywords: paranatrolite, Mont St-Hilaire, Québec, tetranatrolite, zeolite, gonnardite.
© 1980 The Canadian Mineralogist