Colemanite ore, a berate mineral, has been used in ceramic glaze recipes due to its low melting point, low solubility and its smoothness on unleaded glazes. In this study, colemanite was added at 2%-10% to a standard glaze recipe and six different recipe samples, including the standard recipe, were preoared. These recipes were applied to industrial-grade ceramic floor tiles. Various physical tests were done on ceramic floor tiles fired at 1180 degreesC in intensity ovens. The results indicate that the physical properties of the floor tiles did not change considerably and that the surface quality and smoothness of the floor tiles improved with 6%-8% colemanite addition.