Potash Feldspar, 5kg

K2O 11.3%, Na2O 3.2%, Al2O3 18.5%, SiO2 65.8% typical. Used as a flux and fusible in clay bodies and medium-high temperature glazes. For glazes - if a recipe lists feldspar or felspar it probably means Potash Feldspar. Glazes with 35%+ feldspar are likely to produce crazing problems, more than 50% will be unbalanced and probably lack adequate glassy formers in the glaze.