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perthitically1930
1930 B. N. Peach & J. HorneChapters 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.