... C)Refractive index e = 1.760 w = 1.768 (Na line)Resistivity 30 C 300 C 900 C 1600 C (cm ... aesthetic processing; 3, TV screen process in sand; 4, silicon crystal yuan of cutting; 5, tooth die of clean sand; 6, precision foundry sand; Edit ... of high-end products, technology or hardware product surface beautification processing, sand surface white without any impurities, sparing cleaning trouble. Fine, ...