Zirconium is a chemical element with symbol Zr and atomic number 40. The name of zirconium is taken from the name of the mineral zircon, the most important source of zirconium. The word zircon comes from the Persian word zargun زرگون, meaning “gold-colored”. It is a lustrous, grey-white, strong transition metal that resembles hafnium and, to a lesser extent, titanium. Zirconium is mainly used as a refractory and opacifier, although small amounts are used as an alloying agent for its strong resistance to corrosion. Zirconium forms a variety of inorganic and organometallic compounds such as zirconium dioxide and zirconocene dichloride, respectively. Five isotopes occur naturally, three of which are stable. Zirconium compounds have no known biological role.
Zirconium is a lustrous, greyish-white, soft, ductile and malleable metal that is solid at room temperature, though it is hard and brittle at lesser purities. In powder form, zirconium is highly flammable, but the solid form is much less prone to ignition.
Zirconium is used in metal alloys to improve corrosion resistance. It is used as fuel cladding in nuclear reactors due to its low thermal neutron absorption. Zirconium oxide is a good adsorbent for arsenic.
Zirconates are primarily used in manufacturing of piezo ceramics. Although zirconates them selves are water soluble, when coupled with various metals (such a barium or lead) they form insoluble compounds.