In this study, the abrasive properties of periwinkle shell and crab shell grains with the binding effect of polyester resin at high concentration were evaluated. The abrasive properties considered were the hardness, compressive strength and wear resistance. The shells were processed into grit standards by crushing, grinding and then sieving using ASTM E11 set of sieves into grain sizes of P40 and P60. Furthermore on, the grits were developed into polymer matrix composite with particles varying from 96 wt.% to 92 wt.% and resin 3 wt.% to 7 wt.% with 1 wt.% each of cobalt naphthalene and methyl ethyl ketone peroxide hardener respectively by mixing and mold compression using a hydraulic press. It was found that, with an increase in polyester resin content, the hardness and compressive strength increased, while the wear rate decreased. The composition with most improved abrasive properties was 92 wt.% periwinkle shell grains to 7 wt.% polyester resin.