... normally because of the different Country of Origin with the different types and quantity of impurities, resulting ... refractive index, birefringence, absorb light directly; magnetic susceptibility low, non-conductive; the melting point of 2550 °C ... Their theoretical compositions are ZrO2 and SiO2, and a small amount of Fe2O3, CaO, Al2O3, and other ... , etc.). 2012 HOT SELL zirconium sand with good quality