Lueshite

lueshite

neptunite

ilmenite

perovskite

Images

Formula: NaNbO3
Simple oxide, perovskite group, orthorhombic paramorph of isometric isolueshite, monoclinic natroniobite and trigonal pauloabibite
Specific gravity: 4.44
Hardness: 5½
Streak: Grey
Colour: Black
Environments

Plutonic igneous environments
Carbonatites
Metamorphic environments

Localities

At the Poudrette quarry, Mont Saint-Hilaire, La Vallée-du-Richelieu RCM, Montérégie, Quebec, Canada, lueshite occurs in sodalite xenoliths associated with an intrusive alkalic gabbro-syenite complex with sodalite, ussingite, villiaumite, steenstrupine, griceite, eudialyte and lovozerite (HOM ).

At the type locality, the Lueshe mine, Bwito, Rutshuru Territory, North Kivu, DR Congo, lueshite occurs as incrustations on a compact yellow mica that occurs at the contact of cancrinite syenite with carbonatite containing pyrochlore (AM 46.1004-1004).

At Igdlunguaq, Tunulliarfik Fjord, Ilímaussaq complex, Narsaq, Kujalleq, Greenland, Denmark, lueshite occurs in veins cutting nepheline syenite associated with neptunite, analcime, altered eudialyte, and rarely with sphalerite (AM 44.1327 as igdloite, Dana).

At the Gem Park complex, Fremont county, Colorado, USA, lueshite is a common accessory mineral in carbonatite, formed during fenetisation of pyroxenite and gabbro. Associated minerals include vermiculite, ilmenite, pyrochlore, thorianite, perovskite, fersmite and dolomite (HOM, Dana ).

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