Black, frangible and sharp, good thermal conductivity and electric conductivity.
Microcosmic shape is a hexagonal crystal, Mohs hardness is 9.2., Vickers hardness is 3000-3300 kg/mm, microhardness is 3000-3300kg/mm3. Among abrasives, silicon carbide’s hardness is higher than corundum, and ranked below diamond, CBN and boron carbide. Density generally viewed is 3.20g/ mm3 , density of heap is 1.2-1.6g/ mm3 , specific gravity is 3.203.25. Raw material of green silicon carbide are petroleum coke and quality silicon sand, appended with salt, then smelt in electric arc furnace. Compared with green silicon carbide, the purity, hardness and brittleness of black silicon carbide are lower .