meionite


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meionite

(ˈmaɪəˌnaɪt)
n
(Geological Science) a scapolite, Ca4Al6Si6O24CO3, that is isomorphous with marialite
References in periodicals archive ?
Meanwhile, in his Mineral Zone warehouse on North Main Street (mentioned earlier), Marcus Origlieri offered about 20 loose, fat, medium-purple, partially gemmy crystals of meionite (the most common of the three members of the scapolite group), from Badakhshan.
At locality 5 (FPS deposit) it occurs as 0.5-mm colorless, translucent to transparent trapezohedral crystals and shells in cavities in heavily etched meionite. While morphologically cubic, lower symmetry is apparent optically in these crystals, with sector zoning and weak anisotropy evident.
At locality 44, pseudomorphs of albite after trapezohedral analcime crystals up to 1 cm were found in fine-grained, massive laumontite associated with meionite, titanite, fluorapatite and rare zircon.
Scapolite of undetermined composition (meionite or marialite) was observed as small anhedral grains in gray-colored bands consisting of quartz, calcite, fine-grained grossular and subordinate wollastonite.
Analyses performed in the scapolites from this deposit (Table 1) show marialite contents very near to 50%, but slightly higher than meionite.
Scapolite (not specified as marialite or meionite) was reported from the Niessa-Isabela pegmatites (DSGM, 1974).
Relationship to other species: A member of the scapolite group; specifically, the sulfate-dominant analogue of meionite.
Most of these species, plus excellent microcrys-tal specimens of sodalite, meionite, hauyine and sodalite, are easily obtainable by exchange.
Still, the big pieces were admired as uniquely instructive, especially his large Siberian beryl, his large meionite crystal group from Vesuvius, a large proustite/pyrargyrite from the Harz Mountains, and a big native silver from "Spanish America."