The Collaborative International Dictionary
KAlSi2O6
Leucite \Leu"cite\ (l[=u]"s[imac]t), n. [Gr. leyko`s white: cf. F. leucite.]
(Min.) A mineral having a glassy fracture, occurring in translucent trapezohedral crystals. It is a silicate of alumina and potash KAlSi2O6. It is found in the volcanic rocks of Italy, especially at Vesuvius.
(Bot.) A leucoplast.