| 释义 |
spherulite|ˈsfɛr(j)ʊlaɪt|
Also 9 sphærolite, spherolite, sphærulite.
[f. L. sphærula spherule + -ite1 2 a and 2 b; in sense 1, ad. G. sphærolit (now sphärolit) (A. G. Werner, a 1816: see W. G. W. Becker Journal einer Bergmännischen Reise (1816) II. p. vi).]
1.
†a. Min. A concretionary substance found in small spherular masses in certain rocks. Obs.
1823W. Phillips Min. (ed. 3) 209 Sphærulite..occurs in small roundish masses, sometimes aggregated in the botryoidal form. c1840Encycl. Metrop. VI. 516/1 Sphærulite..occurs in small spheroidal and botryoidal masses imbedded in pearlstone and pitchstone. 1862Dana Min. 357 Spherulite is a kind of pearlstone, occuring in small globules in massive pearlstone. 1889Science-Gossip XXV. 47 Spherulite and pitchstone from Arran.
b. Geol. A small spheroidal mass found in rock; spec. one consisting of many crystals which have grown radially from a point.
1829Trans. Geol. Soc. II. 202 A previous separation had taken place of the feldspathose spherolites. 1844C. Darwin Geol. Observations on Volcanic Islands iii. 58 The sphærulites are either white and translucent, or brown and opaque. 1856Q. Jrnl. Geol. Soc. XII. 340 The multiplication and confusion of these crystallites or sphærulites ultimately destroy the glassy character of the substance altogether. 1863Dana Man. Geol. §8. 88 [Pearlstone] often contains spherical concretions, called spherulites, which consist of feldspar with an excess of quartz. 1868Mem. California Acad. Sci. I. 52 Small globular grains, from the size of a pin-head to that of a rifle bullet, called ‘sphærolites’ by Beudant. 1886Geikie Class-Bk. Geol. 214 In some obsidians, little spherulites of a dull grey enamel-like substance have made their appearance. 1909J. P. Iddings Igneous Rocks I. vi. 230 Such spherulites..consist of radiating prisms of alkali feldspar with submicroscopic graphic intergrowths of quartz. 1931[see orbicule]. 1939W. H. Twenhofel Princ. Sedimentation xv. 570 Spherulites with radiate structure are evidently a form of crystal aggregate, whereas those with amorphous internal structure are either excremental particles or colloidal aggregates as glauconite, greenalite, or chamoisite. 1974A. C. Tennissen Nature of Earth Materials v. 280 Spherulites have a radial type of internal structure.
c. A small spheroidal mass of crystals or fibrils of any substance, esp. a polymer.
1893Mineral. Mag. X. 97 (table) LiNaSO4... Spherulitic... Some of the spherulites have a radial structure. 1911Chem. Abstr. V. 1052 The author describes the peculiar structure of spherulites obtained in cholesterol and β-naphthalene benzoate. 1933Bureau of Standards Jrnl. Res. (U.S.) X. 488 The microscopical examination of the crystals of rubber hydrocarbon indicates that they are spherulites composed of many fine needles. 1963New Scientist 7 Nov. 334/1 Some polymers, like nylon and polystyrene are highly crystalline. They do not normally form single crystals, however, but produce so-called spherulites which are clusters of plate-like or needle-like individual crystals. 1975Sci. Amer. Dec. 99/1 The spherulite, or ‘sunburst’ microstructure normally results from crystallization under quiescent conditions.
2. Palæont. (With capital initial.) A genus of fossil molluscs.
In early use in L. form Sphærulītēs.
1834Griffith tr. Cuvier XII. 92 Sphærulites,..where the valves are roughened by irregularly raised plates. 1841Miller O.R. Sandst. viii. 153 The hippurites, sphærulites, and nummulites of the same formations, in Greece, Italy, and Spain. 1847Ansted Anc. World x. 241 One such genus is called Sphærulite... They seem most nearly allied to the inhabitants of those univalve shells of which the limpet is the present representative. |