Nepheline

Nepheline (from Ancient Greek (nephélē)'cloud'), also called nephelite, is a rock-forming mineral in the feldspathoid group – a silica-undersaturated aluminosilicate (Na₃KAl₄Si₄O₁₆) that occurs in intrusive and volcanic rocks with low silica, and in their associated pegmatites. It is used in glass and ceramic manufacturing and other industries, and has been investigated as an ore of aluminium.