... as hard as diamonds. Features: 1.Special Materials: Using high-tech Zirconia crafted, high-density, high hardness, never wear, hardness (HRA87) is next to ... BOX X1Test result:Cut one apple with a sharpened stainless steel knife and another with a ceramic knife. After 15 minutes ... at all (see right picture below), while the one cut with metal knife already showed some signs of discoloration. Fruits will ...