et off fireworks of color on your pieces with Duncan® Crystals Glazes™! These unique glazes create bright, multicolored bursts and specks when fired, resulting in a different finish every time. With Crystals Glazes, color crystals move throughout the glaze during firing, creating a distinctively interesting appearance. Each result depends on the size of the crystal, slope of the piece and temperature of the fire. Like the excitement of fireworks festivities, you’ll love the pops of color from Crystals Glazes!