Terminology of “potassium feldspar” and “alkali feldspar”

The usage of “potassium feldspar” and “alkali has been confused in earth sciences for a long time. term is the solid solution series between two components KAlSi3O8 (potassium feldspar) NaAlSi3O8 (sodium feldspar), including more or less CaAl2Si2O8 (lime as third component. practice an end member feldspar solution. At present, scientific appropriate terms without confusion needed sciences. This review outlines history hitherto terms, interprets how important sciences, especially mineralogical petrological We recommend that perthite should be termed not but alkali feldspar, potassium applied to at least with content ≥ 90 mol%.