What is a missourite in geology ?

Missourite : definition

A missourite is an exceptional plutonic rock containing leucite (nearly 16%), augite or diopside (sometimes 50%), olivine, oxides of iron and titanium, biotite, apatite and analcime. It is mainly found in blocks raised by the lava. Leucitite is its volcanic equivalent, it is a feldspathoidite.
Streckeisen diagrams (or QAPF diagrams) - Classification of plutonic and volcanic rocks