Product Description: Made of alumina, it has a higher hardness and abrasion resistance compared to agate mortar. ■ In addition to preserving the purity of grinding, it is also suitable for grinding hard objects (mineral, etc.) Product specifications: Mortar. Outer diameter x inner diameter: 6.7 x 5.1 inches (170 x 130 mm). Specific gravity: 3.6. Chemical composition: Al2O3/93%, SiO2/5%. Square type. Model number: HD-3 characteristics/notes. *The mortar and pestle are ceramics, so there may be slight differences in the finished dimensions shown in the dimensions of the listed measurements. Please consider it as a guide. Manufacturer: Nikato.