Publication Type:

Journal Article

Authors:

McDonald, Andrew M.; Chao, George Y.

Source:

The Canadian MineralogistThe Canadian Mineralogist, Mineralogical Association of Canada, Ottawa, ON, Canada, Volume 42, Part 3, p.769-780 (2004)

ISBN:

0008-4476

Keywords:

alkali metals, alkaline earth metals, alteration, calcium, Canada, chemical composition, concentration, crystal structure, eastern canada, genesis, geochemistry, hydration, inclusions, infrared spectra, marbles, metals, Metamorphic rocks, mineral assemblages, Mont-Saint-Hilaire Quebec, new minerals, optical properties, petrography, quebec, Rouville County Quebec, silicates, sodium, spectra, x-ray diffraction data, xenoliths

Abstract:

Haineaultite occurs in altered marble xenoliths at the Poudrette quarry, Mont Saint-Hilaire; it was formed by the interaction of incompatible-element-rich late-stage fluids with the marble. At least some of these marble xenoliths were derived from limestones of Silurian rather than Grenvillian age. Crystals are generally lemon-yellow or more rarely tan, off-white or pale orange; they occur as isolated prismatic crystals or fan-like aggregates of more tabular crystals elongate on [001], up to 6 mm long. Associated minerals are pectolite, fluorapophyllite, vesuvianite, tainiolite, albite (pink), fluorite, calcite, microcline and aegirine. The mineral has a vitreous lustre; H. 3-4, D (sub calc) 2.28 g/cm (super 3) ; distinct to good cleavages on {100}, {010} and {001}; alpha 1.599, beta 1.610, gamma 1.696, 2V (sub gamma ) 41 degrees ; alpha = b, beta = c, gamma = a. EPMA gave SiO (sub 2) 42.70, TiO (sub 2) 18.86, ZrO (sub 2) 0.31, Nb (sub 2) O (sub 5) 5.56, FeO 0.49, MnO 0.25, CaO 9.99, MgO 0.07, Na (sub 2) O 4.70, K (sub 2) O 2.09, SO (sub 3) 2.60, F 0.17, H (sub 2) O(calc) 10.11, less O = F 0.07, = 97.83, leading to the idealized formula (Na,Ca) (sub 5) Ca(Ti,Nb) (sub 5) (Si,S) (sub 12) O (sub 34) (OH,F) (sub 8) . 5H (sub 2) O. Indexed XRD powder data are tabulated; strongest lines 11.564(100), 6.932(90), 3.052(75), 2.977(70), 5.258(40), 4.446(40), 2.582(40) Aa; a 7.204, b 23.155, c 6.953 Aa, V 1159.8 Aa (super 3) , (super ) Z = 1, space group C222. The IR spectrum is presented. The structure was refined to R 5.41 % and consists of eight-membered rings of SiO (sub 4) tetrahedra linked to adjacent rings to form vierer double chains along [001], which are cross-linked by TiO (sub 6) (super ) octahedra to give a mixed tetrahedron-octahedron titanosilicate framework similar to that found in zorite. Channels running parallel to [100] are occupied by Ca and H (sub 2) O, with Na occupying channels parallel to [001]. The name is for Gilles Haineault of St-Mathieu de Beloeil, Quebec, well-known collector of Mont Saint-Hilaire minerals.

Notes:

GeoRef, Copyright 2018, American Geological Institute.<br/>2005-013578<br/>haineaultite<br/>titanosilicates