Leucite

Definitions

  • Webster's Revised Unabridged Dictionary
    • Leucite (Bot) A leucoplast.
    • 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.
    • ***
Century Dictionary and Cyclopedia
    • n leucite A mineral originally found in the recent volcanic rocks of southern Italy, especially at Vesuvius, disseminated through the lavas in crystals, usually trapezohedrons, or in irregular masses. It has also been observed similarly associated in some other regions, as the Eifel in Rhenish Prussia, the Leucite Hills of Wyoming, etc.; but it is in general of very limited occurrence. It is a silicate of aluminium and potassium, and has a white or grayish color. It was very early called white garnet, from its similarity to garnet in crystalline form; and it is also called amphigene. Leucite has excited much interest because of the phenomenon of double refraction which its crystals exhibit, this being at variance with the usually accepted isometric form. On account of these “optical anomalies,” and because also of certain variations in external form, it has been referred to the tetragonal (or orthorhombic) system. Recent investigations have shown, however, that at a temperature of 500°C. it becomes isotropic, and hence it is inferred that when formed it was normally isometric, and that the observed variations in form and optical character have resulted from subsequent molecular changes.
    • n leucite A small yellowish body found in the cotyledons of a germinating plant that has not been exposed to sunlight.
    • ***
Chambers's Twentieth Century Dictionary
    • n Leucite lū′sīt a whitish mineral occurring only in volcanic rocks
    • ***

Etymology

Webster's Revised Unabridged Dictionary
Gr. leyko`s white: cf. F. leucite,
Chambers's Twentieth Century Dictionary
Gr. leukos, white.

Usage

In literature:

The flows from Kibo include nepheline and leucite basanite lavas rich in soda felspars.
"Encyclopaedia Britannica, 11th Edition, Volume 4, Part 3" by Various
Leucite, potash in, 220.
"Manures and the principles of manuring" by Charles Morton Aikman
Similarly there are leucite-basalts and leucite-basanites.
"Encyclopaedia Britannica, 11th Edition, Volume 3, Part 1, Slice 3" by Various
In the lava of Vesuvius leucite is an essential, and perhaps the most abundant mineral.
"Volcanoes: Past and Present" by Edward Hull
Leucite and nepheline rocks have been found in various parts of the island, especially in the south-west.
"Encyclopaedia Britannica, 11th Edition, Volume 5, Slice 5" by Various
These observations led me to reject the opinion of those who hold that crystals of leucite are pre-existent in the lava.
"The Eruption of Vesuvius in 1872" by Luigi Palmieri
The "pseudo-leucites," as they have been called, measure one-quarter to three-quarters of an inch across.
"Encyclopaedia Britannica, 11th Edition, Volume 4, Slice 3" by Various
DUBOIS, R.: 1919a, b, Symbiotes, Vacuolides, Mitrochondries et Leucites.
"The Nature of Animal Light" by E. Newton Harvey
They are chiefly leucite and nepheline rocks, such as leucitite, leucitophyre and nephelinite, but basalt and trachyte also occur.
"Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2" by Various
Leucite and nepheline lavas are here abundant.
"Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 7" by Various
Analcite, leucite and garnet often crystallize in the simple form {211}.
"Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7" by Various
Some of the volcanoes, however, have erupted leucite rocks.
"Encyclopaedia Britannica, 11th Edition, Volume 15, Slice 3" by Various
***