... density brown fused aluminum oxide abrasive, used for coated abrasive products. The high temperature heat treatment ... Alpha alumina trigonal systemSpecific Gravity 3.94Hardness 2090 Knoop scale, 9.0 Mohs scaleMagnetic Material 0 ... , high temperature treated brown fused aluminium oxide,fused brown corundum,corundum,brown fused alumina,brown aluminium oxide,fused alumina brown fused alumina FEPA P grit