... rusted and discoloration; 4. white Ceramic knife 5,LFGB,EU,SGSCeramic Knife – High Density ZirconiaItem No.: JH3A1 ... 5", 6", 7" ceramic knife A seriesBlade Material: zirconium dioxide (ZrO2; also known as zirconia)Blade Colour: white, ... made by Zirconium ceramics materials which called “ceramic steel”, have the properties as sharp-edged ... , enjoy the gourmet flavor! GOOD quality zirconia ceramic knife