Nepheline

Also called �nephelite�, or �eleolite� the 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. Nepheline is the characteristic mineral of alkaline plutonic rocks, particularly nephelinesyenites and nephelinegneisses. It occurs in beautiful crystal form with mica, garnet,