nepheline

/nef"euh lin/, n.

a feldspathoid mineral, essentially sodium aluminum silicate, NaAlSiO₄, occurring in alkali-rich volcanic rocks.

Also, nephelite /nef"euh luyt'/.

[1805-15; < F néphéline, equiv. to néphél- ( < Gk nephéle cloud) + -ine -INE²]

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or nephelite

Most common feldspathoid mineral, an aluminosilicate of sodium and potassium (Na₃KAl₄Si₄O₁₆).

It is sometimes used as a substitute for feldspars in the manufacture of glass and ceramics.

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▪ mineral

also called  nephelite , or  eleolite 

 the most common feldspathoid mineral, an aluminosilicate of sodium and potassium [(Na,K)AlSiO₄]. It is sometimes used as a substitute for feldspars in the manufacture of glass and ceramics. Nepheline is the characteristic mineral of alkaline plutonic rocks, particularly nepheline syenites and nepheline gneisses. It occurs in beautiful crystal form with mica, garnet, and sanidine feldspar on Monte Somma, Vesuvius, Italy. For detailed physical properties, see feldspathoid (table).

      Carnegieite is synthetic, high-temperature nepheline. kaliophilite is the high-temperature form of kalsilite, the potassium-rich variety of nepheline. Kaliophilite is unstable at normal temperatures and rarely occurs in nature.

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