Licencing requirement for Zirconium silicate (ZrSiO4) with content of > 62% (Zr02 + HfO2) d50=1.1±0.2 µm; Zirconium silicate (ZrSiO4) with content of > 64%( ZrO2 + HfO2) passing sieve of 325 mesh > 95%; Zirconia in form of powder/sandstone > 99% (Zr02+HfO2)