- a feldspathoid mineral, essentially sodium aluminum silicate, NaAlSiO4, occurring in alkali-rich volcanic rocks.
Origin of nepheline
Examples from the Web for nepheline
Historical Examples of nepheline
The pyroxene is morphic, yellow or green, and is surrounded by formless areas of nepheline.
These last consist of an intermixture of nepheline or sodalite and alkali-felspar.
Nepheline appears to decrease in amount as leucite increases.
Sodalite or hauyne may also be present, but nepheline is typically absent.
Some writers held that this mineral has resulted from the decomposition of nepheline; others regard it as a primary mineral.
- a whitish mineral consisting of sodium potassium aluminium silicate in hexagonal crystalline form: used in the manufacture of glass and ceramics. Formula: (Na,K)(AlSi) 2 O 4