... - walnut shell grains. Compared with the old pore-forming material-- refined naphthalene, our product has uniform pores, and it ... ± 0.05g/cm Color: Yellow-brown granules 2 [Polishing Material] walnut shellSuch polishing materials processed by the special process have ... ,beautiful, brown. High-quality fruit (coconut, apricot) shell as raw materials, it is refined handled and screening made by water ...