Dalekanium

Dalekanium is the metal material that Dalek casings are made of. Whether this is a real metal or an alloy is unknown.

In an alternate timeline, Dalekanium was an unstable explosive used to penetrate Dalek casings. (DW: Day of the Daleks) The term itself is probably a neologism used to describe a product of the Daleks.

The dalekanium which Dalek armour is made of is composed of "bonded polycarbide". (DW: Remembrance of the Daleks, Doomsday)

Dalekanium can also attract gamma radiation. Dalekanium panels were attached to the Empire State Building in 1930 to attract gamma radiation, which would introduce Dalek DNA into Humans that the Cult of Skaro had captured. (DW: Evolution of the Daleks)

Metalert is a reinforced type of Dalekanium. The casing is infused with Fildor gold and sap from the extinct Arkellis flower. The rareness of these substances meant that only Dalek Sec used this substance. (DWF: Birth of a Legend)