Search results for "Nepheline" - New World Encyclopedia

occurs in low silica igneous syenite and nepheline syenite intrusives. Other ... with dunites in North Carolina and from a nepheline syenite in Craigmont, Ontario ...

undersaturated pyroxenite (essexite), and nepheline syenite. ... silica-undersaturated minerals such as nepheline and other feldspathoids. ...

with silica, resulting in the formation of nepheline. (Silica saturation of a rock can be evaluated by normative mineralogy.) Gabbro is generally ...

of igneous rocks rich in sodium, such as nepheline-syenite and phonolite. Pargasite is a rare, magnesium-rich amphibole with essential sodium ...

Minerals such as alkali feldspar, leucite, nepheline, sodalite, phlogopite mica, and apatite may be present in the groundmass. Basalt has high ...