Leucite
Leucite (lū"sīt) , noun
[Greek leyko`s white: compare French leucite.]
1.
(Mineralogy) 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.
2.
(Botany) A leucoplast.