perthiticadj.
/pəːˈθɪtɪk/, U.S. /pərˈθɪdɪk/ Geology.
Of, relating to, or resembling perthite or its texture.
ΘΚΠ
the world > the earth > minerals > mineral sources > [adjective] > yielding a mineral or metal > others
amethystine1670
marcasitical1670
cawky1676
blendy1683
sylvanitic1796
ytter1805
phosphatic1818
pyroxenic1819
hornblendic1823
muriatiferous1823
platiniferous1828
quartziferous1831
hypersthenic1838
schorly1838
uralitic1845
blendous1847
rutilated1849
orthoclase1853
palladiferous1866
peridotic1867
paragonitic1868
vivianitized1870
andesitic1876
tremolitic1880
phosphoriferous1881
kaolinitic1885
saussuritic1885
perthitic1887
strontianiferous1888
radiferous1899
myrmekitic1916
montmorillonitic1939
illitic1949
the world > the earth > minerals > types of mineral > silicates > tectosilicate > [adjective] > feldspar > varieties of feldspar
orthoclase1853
andesitic1876
saussuritic1885
perthitic1887
myrmekitic1916
1887 Amer. Naturalist 21 765 J. Lehmann explains the perthitic structure of certain of the feldspars by supposing that one of the minerals, as albite in perthite, is secondary, and fills cracks in the other.
1906 J. P. Iddings Rock Minerals ii. 236 Perthitic intergrowth.
1949 Econ. Geol. 44 174 In the diorite facies the microcline is generally only slightly perthitic..whereas in the syenitic rock it is ordinarily highly perthitic.
1990 C. Pellant Rocks, Minerals & Fossils 13 Perthitic granite. A coarse-grained rock with much grey vitreous quartz.
Derivatives
perˈthitically adv. in the manner of perthite.
ΘΚΠ
the world > the earth > minerals > types of mineral > silicates > tectosilicate > [adverb] > perthite or feldspar
perthitically1930
1930 B. N. Peach & J. Horne Chapters Geol. Scotl. 112 The alkali-felspar includes both orthoclase and albite, which may be present separately, perthitically intergrown.
1949 Econ. Geol. 44 179 The sodic solutions soaked into the microcline and replaced it perthitically by albite.
This entry has been updated (OED Third Edition, December 2005; most recently modified version published online March 2022).
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adj.1887