Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Zirconocene dichloride is an organometallic compound composed of a zirconium central atom, with two cyclopentadienyl and two chloro ligands. Zirconium is a chemical element with the symbol Zr and atomic number 40. Its atomic mass is 91.224. It is a lustrous, grey-white, strong transition metal that resembles titanium. Zirconium is used as an alloying agent for its strong resistance to corrosion. It is never found as a native metal; it is obtained mainly from the mineral zircon, which can be purified with chlorine. Zirconium was first isolated in an impure form in 1824 by Jöns Jakob Berzelius.