leucite Min.
(ˈl(j)uːsaɪt)
Also 8 leucit.
[a. G. leucit (A. G. Werner, 1791), f. Gr. λευκός white: see -ite.]
Silicate of aluminium and potassium, usually found in glassy trapezohedrons, occurring in volcanic rocks, esp. in lavas from Vesuvius.
| 1799 Med. Jrnl. I. 300 In the decomposition of the fossil, called leucit, he [Klaproth] found from 20 to 22 parts of potass in the hundred. 1800 Henry Epit. Chem. (1808) 363 The volcanic leucite contained less potash than other kinds. 1876 Page Adv. Text-Bk. Geol. vii. 146 Many of the older lavas yield agates..leucite..and other precious minerals. |
| attrib. 1878 Lawrence tr. Cotta's Rocks Class. 135 Leucite rock may be regarded as a dolerite, in which the labradorite is replaced by leucite. |
Hence
leuˈcitic a., containing or of the nature of leucite.
ˈleucitoid (
Crystallogr.), the trapezohedron or tetragonal trisoctahedron; so called as being the form of the mineral leucite.
leuˈcitophyr(e [G. (
por)phyr porphyry;
cf. granophyre], ‘a dark-grayish fine-grained cellular volcanic rock consisting of augite and leucite together with some disseminated magnetic iron’ (Dana
Man. Geol. 1868).
| 1830 Lyell Princ. Geol. I. 352 The foundations of the town [Pompeii] stand upon the old leucitic lava of Somma. 1879 Rutley Study Rocks x. 109 As in the little leucite crystals of the sperone or leucitophyr which occurs near Rome. 1880 G. F. Rodwell in Nature XXI. 352 The lava is very leucitic. |