Nepheline Syenite A 270 is an anhydrous sodium potassium alumino silicate. An excellent source for soda. Although feldspar-like in its chemistry, mineralogically it is an igneous rock combination of nepheline, microcline, and albite. Nepheline syenite melts lower than feldspars. Like feldspar, nepheline syenite is used as a flux in tile, sanitary ware, porcelain, vitreous and semi-vitreous bodies. and minor minerals like mica, hornblende and magnetite. Similar to a soda spar. It can reduce crazing tendencies when added to a clay body. Also used in glazes where a soda spar is required.