Zirconium Iron Pink (peach, coral) Zircon, an inorganic pigment, is a reaction product of high temperature calcination in which Zirconium (IV) Oxide, Silicon (IV) Oxide, and Iron (III) Oxide in varying amounts are homogeneously and ionically interdiffused to form a crystalline matrix of zircon. Its composition may include any one or a combination of the modifiers alkali or alkaline earth halides.