... materials - walnut shell grains. Compared with the old pore-forming material-- refined naphthalene, our product has uniform pores, and it is ... .85 ± 0.05g/cm Color: Yellow-brown granules 2.Polishing Material] walnut shellSuch polishing materials processed by the special process have ... process of spectecles, jewelry, button, stamping parts, electronic parts, etc. High quality garnet Abrasive