| 释义 |
nepheline Min.|ˈnɛfəlɪn|
Also -in, erron. nephiline.
[a. F. néphéline (Haüy, 1800), f. Gr. νεϕέλη cloud, because its fragments are rendered cloudy by immersion in nitric acid.]
A double silicate of aluminium and sodium, occurring chiefly in volcanic deposits in Italy. nepheline-syenite [ad. G. nephelin-syenit (H. Rosenbusch Mikrosk. Petrogr. (1877) II. 203)], a rare plutonic rock which resembles syenite in containing alkali feldspars such as orthoclase as essential minerals and usu. dark ferromagnesian minerals also (commonly amphibole or pyroxene), but differs in containing nepheline as an additional essential mineral, in being rich in soda but always lacking quartz, and in the frequent occurrence of rare minerals as accessories.
1814J. Black tr. Berzelius' Min. 45 Nephelin. 1852Th. Ross tr. Humboldt's Trav. I. ii. 51 We could discover neither nepheline, leucite, nor feldspar. 1877Nature XV. 384/1 Mineralogists have often been troubled to distinguish with certainty between apatite and nephelin. 1892F. H. Hatch Text-bk. Petrol. (ed. 2) vi. 143 The syenites and diorites are plutonic granitoid rocks, less acid than granite, and consequently containing little or no free silica. They may be divided into—Syenites. Nepheline-syenites. Diorites. 1938A. Johannsen Descr. Petrogr. Ign. Rocks IV. 78 The nepheline-syenites are generally gray rocks with a greasy luster, usually moderately dark... Yellows, reds, and blues are not unknown. 1967M. J. Coe Ecol. Alpine Zone Mt. Kenya 11 The lava cooled slowly and produced a material that is highly crystalline. These rocks are called nepheline-syenite and contain large Felspar crystals up to 3 cm long as well as smaller nepheline crystals.
attrib.1863Dana Man. Geol. 89 Nephelinite, nephelin dolerite. 1882Geikie Text-bk. Geol. II. 150 Nepheline Rocks. 1888Teall Brit. Petrogr. 360 The olivine-bearing rocks [of Nephelinite] are termed nepheline-basalts.
Hence nepheˈlinic a. (Cassell, 1886.) |