It occurs interlayered with chlorite, biotite and phlogopite. Consumption of muscovite and phlogopite splittings was about 308 t in 2008. It is associated with various mixed iron-titanium oxides, graphite, analcime, diopside, ilmenite, phlogopite and rutile. Vermiculite forms by the weathering or hydrothermal alteration of biotite or phlogopite. Phenocrysts in the rocks contain clinopyroxene, olivine, orthopyroxene and phlogopite. Hornblendite and, rarely phlogopite, are also found. Phlogopite, oxide minerals (ilmenite, perovskite and spinel), apatite and pyrite are also present. Muscovite and phlogopite are used in sheet and ground forms. The basaltic occurrence of phlogopite is in association with picrite basalts and high-alumina basalts. Muscovite and phlogopite splittings can be fabricated into various built-up mica products. In some cases the phlogopite is considered to be produced by autogenic alteration during cooling. Phlogopite is an important and relatively common end-member composition of biotite. Phlogopite is found as small metamorphic crystals in marble xenoliths within the syenite.