... -4.71, 1.93-2.01 refractive index, birefringence, absorb light directly; magnetic susceptibility low, non-conductive; the melting point of ... dioxide, zirconium oxychloride, zirconium, sodium fluorozirconate, potassium, zirconium sulfate, etc.). 60%63% 65% 66% best price Zircon Sand for sale