It occurs in nepheline syenite intrusives and in nepheline syenite pegmatites. It also occurs in low-silica igneous syenite and nepheline syenite intrusives. It is known from plutonic nepheline syenite rocks. The similar rock without quartz and nepheline is denominated alkaline syenite or syenite. Its intrusive equivalent is nepheline syenite. It is called nepheline syenite gneiss or litchfieldite. It is essentially a microcline, sodalite and cancrinite variety of nepheline syenite. Phonolite is a fine-grained equivalent of nepheline syenite. Fresh clear microcline is very characteristic of some types of nepheline syenite. Macroscopic aspects of nepheline syenite are similar to those of granite. Extremely iron-rich olivine is rare, but is present in some nepheline syenite. It occurs with other zeolites, olivine, augite and nepheline. Associated minerals include ilmenite, zirkelite, apatite, magnetite, perovskite, fluorite, nepheline, pyrochlore and allanite. The normative mineralogy of this average composition contains about 22% nepheline and 66% feldspar. It contains also orthoclase, nepheline, biotite, aegirine, acmite.